I got some new regs and got to dive them today.
I used a ScubaPro Mk 25 EVO 1st stage with a G260 and an S620Ti connected to it. Both regs were on 40" hoses with a Cave Adventures swivel on each, so that everything would be as apples-to-apples as I could make it.
I got in the local quarry and switched back and forth a couple of times relatively shallow. Then I dropped down to the bottom, which is 90', and swapped back and forth a few times.
My conclusion is that I could feel a difference and it felt like, when I inhaled, the G260 just had a little extra rush of air coming in, compared to the 620. Now, that could be as simple as a swirl effect in the air that made it feel a little more turbulent or made it feel "cooler" coming into my mouth. So, I'm not trying to suggest that there is anything objective about my observation. I'm not trying to say the G260 breathed "better" or had lower Work Of Breathing. All I'm saying is that the G260 FELT better, to me. It FELT like there was more of a rush of air once the air started flowing.
I didn't really notice any difference on the exhale. But, on reflection, I don't remember ever really focusing on the feel of the exhale with either reg. Maybe if I focused on the exhale I might notice a difference. Not sure.
The regs are all brand new. I did not adjust the tuning on any of them from taking them out of the boxes. Before I got in the water with them, I did check them by setting the venturi switch to Pre-dive and tapping the purge. Both regs would blast a little air. Then I set the venturi switch to Dive and tapped the purge. Both regs would go into instant free flow.
All the older, wiser heads at my shop told me that the G260/Mk 25 setup was the nicest breathing reg set any of them had used. But, the ScubaPro instructor that taught my reg tech class said that the S620 has something like a 30% improvement in work of breathing over the S600. None of the folks at my shop have actually dived the 620. So, I really wanted to compare them for myself. I really wanted the 620 to breathe as nicely as the 260, so I could standardize my gear on the smaller, lighter regs. The 620 costs more, but I would pay the extra if it breathed as nicely and was also smaller and lighter (bonus: less likely to get corrosion inside, too). Oh, well. I guess I'll be buying more of the less expensive ones. Bummer...
I also have a Hollis DC3/212 reg set and a Dive Rite XT1/XT2 reg set, both of which I have been using for something like 2 - 3 years. I did not try those today to get an immediate comparison. But, I have dived them fairly recently. I didn't notice the S620Ti feeling any better or easier to breathe than either of those. The Hollis, the Dive Rites and the S620Ti all seem to breathe just fine, to me. I can't really say, right now, after only 2 dives with the 620s (that's my disclaimer here) that I would pick any of them over the other, for how they work. But, I definitely can say that I could feel just a little difference with the G260 and I would (and will) choose it over any of those others in the future.
The G260 is heavier (not that the weight meant ANYTHING to me in the water) and bulkier than the 620, so that might affect my choices in one regard. I got 2 of each. I think that I'm going to put the two 620s on a 1st stage together and use that as my single tank, recreational diving reg set for future dive trips where I am flying. I think being lighter and less bulky will be of more benefit to me when flying and trying to fit my regs in my carry-on. Having an S620Ti as my "octo" seems rather decadent. But, I jumped on the "have identical 2nd stages for primary and alternate" bandwagon as soon as I finished my initial open water certification and I haven't found a reason to change on that yet.
I will use the G260s as my regs for any diving I do with doubles. Of course, all technical dives that I do will be with doubles, so the G260s will be my regs for all technical diving. The nicer "feel" of breathing seems like a better choice for longer and/or deeper dives.
Just my thoughts now that I have settled the G260 vs S620Ti debate for myself.
I used a ScubaPro Mk 25 EVO 1st stage with a G260 and an S620Ti connected to it. Both regs were on 40" hoses with a Cave Adventures swivel on each, so that everything would be as apples-to-apples as I could make it.
I got in the local quarry and switched back and forth a couple of times relatively shallow. Then I dropped down to the bottom, which is 90', and swapped back and forth a few times.
My conclusion is that I could feel a difference and it felt like, when I inhaled, the G260 just had a little extra rush of air coming in, compared to the 620. Now, that could be as simple as a swirl effect in the air that made it feel a little more turbulent or made it feel "cooler" coming into my mouth. So, I'm not trying to suggest that there is anything objective about my observation. I'm not trying to say the G260 breathed "better" or had lower Work Of Breathing. All I'm saying is that the G260 FELT better, to me. It FELT like there was more of a rush of air once the air started flowing.
I didn't really notice any difference on the exhale. But, on reflection, I don't remember ever really focusing on the feel of the exhale with either reg. Maybe if I focused on the exhale I might notice a difference. Not sure.
The regs are all brand new. I did not adjust the tuning on any of them from taking them out of the boxes. Before I got in the water with them, I did check them by setting the venturi switch to Pre-dive and tapping the purge. Both regs would blast a little air. Then I set the venturi switch to Dive and tapped the purge. Both regs would go into instant free flow.
All the older, wiser heads at my shop told me that the G260/Mk 25 setup was the nicest breathing reg set any of them had used. But, the ScubaPro instructor that taught my reg tech class said that the S620 has something like a 30% improvement in work of breathing over the S600. None of the folks at my shop have actually dived the 620. So, I really wanted to compare them for myself. I really wanted the 620 to breathe as nicely as the 260, so I could standardize my gear on the smaller, lighter regs. The 620 costs more, but I would pay the extra if it breathed as nicely and was also smaller and lighter (bonus: less likely to get corrosion inside, too). Oh, well. I guess I'll be buying more of the less expensive ones. Bummer...
I also have a Hollis DC3/212 reg set and a Dive Rite XT1/XT2 reg set, both of which I have been using for something like 2 - 3 years. I did not try those today to get an immediate comparison. But, I have dived them fairly recently. I didn't notice the S620Ti feeling any better or easier to breathe than either of those. The Hollis, the Dive Rites and the S620Ti all seem to breathe just fine, to me. I can't really say, right now, after only 2 dives with the 620s (that's my disclaimer here) that I would pick any of them over the other, for how they work. But, I definitely can say that I could feel just a little difference with the G260 and I would (and will) choose it over any of those others in the future.
The G260 is heavier (not that the weight meant ANYTHING to me in the water) and bulkier than the 620, so that might affect my choices in one regard. I got 2 of each. I think that I'm going to put the two 620s on a 1st stage together and use that as my single tank, recreational diving reg set for future dive trips where I am flying. I think being lighter and less bulky will be of more benefit to me when flying and trying to fit my regs in my carry-on. Having an S620Ti as my "octo" seems rather decadent. But, I jumped on the "have identical 2nd stages for primary and alternate" bandwagon as soon as I finished my initial open water certification and I haven't found a reason to change on that yet.
I will use the G260s as my regs for any diving I do with doubles. Of course, all technical dives that I do will be with doubles, so the G260s will be my regs for all technical diving. The nicer "feel" of breathing seems like a better choice for longer and/or deeper dives.
Just my thoughts now that I have settled the G260 vs S620Ti debate for myself.