Is there a picture? So we could see if there's a slot for the crotch strap, and will it take the 2" webbing, and how many camband slots there are.
2 cambands are harder to to deal with when the tank's sandwiched between two other tanks and gunwale.
I looked at a Hydros yesterday. It had one of those molded plastic plates that cradles a tank, and one tank strap.
I don't let anyone else do stuff like swap tanks for me. On a boat (even in rough conditions, like NC on a bad day), I just pull the tank out from the rack onto my actual bench seat to do up the tank straps. With a piece of cave line tied through a slot in my BP, to hold it at the right height on the tank, buckling up my two SP-style QR tank straps is a cinch (pun intended).
I was on a dive boat last week with a guy diving a hydros (along with a variety of other setups, including three people using BPWs, one steel plate, one aluminum and one kydex/plastic). I asked the Hydros guy how he liked his BC and he said he really enjoyed it. He left the integrated weight pockets at home and used a weight belt. I noticed it looked extremely streamlined, did not appear to ride up on him or shift around, and it was dry VERY quickly after dives. He was able to pack it up small enough to carry on board the airline. He was able to travel with just two carry-ons despite having all his own gear.
Once you leave the Hydros pocket things at home, what is the benefit to the Hydros? It seems like it's only that it dries really quickly. But, unlike a BPW, you're stuck with a 40 # wing.
I can fit my BP/W and all my other dive gear (including a full 3/2 wetsuit), except my fins and cutting devices, into 2 carry-ons also. My fins exceed the TSA max length for a carry-on, so I put them in a checked bag with clothes, etc..
BTW, the new AquaLung Outlaw is very minimalist, with optional accessories so you can dress it up to have pockets like the Hydros, etc.. But, the Outlaw has interchangeable wings! They have a 12 # and a 25#. If they produce a 35 - 40# wing, that rig would be a real contender for people who don't want a BP/W, but do want some flexibility/modularity for single tank diving! Actually, it already is, I think.
About the crotch strap. For me, it is a vital part of the BPW as it allows the shoulder straps to be comfortably loose but keeps the overall BCD and tank stable. I am on the thin side and without a crotch strap, my BPW and all other BCD's I have used will ride up. Some with larger stomachs say they don't have that problem because their belly keeps the waist strap down.
Part of the marketing of the Hydros is the monprene backplate is comfortable and creates friction. The friction combined with the adjustable monprene padded shoulder straps, they claim a crotch strap is not necessary, but can be added as an option. I don't believe anything until I try it, but I can see how friction and a tightened down harness would help.
+1 on the crotch strap. I have also taken to positioning my waist belt buckle so that it stays to the left of my crotch strap loop. With it like that, I can slip open the buckle, pull the right side of the waist belt out, and the only left attaching my rig to me is too shoulder straps which, at that point, are nice and loose. I can doff my rig, in the water or out, VERY quickly. But, when it's on, whether I'm diving a single tank or double steel 120s and a deco cylinder, it is totally stable and doesn't move around on me, while at the same time never feeling tight or restrictive in any way. It's just snug - and secured by a 5-point harness. I guess wanting a tight 4-point harness instead is one of those chocolate vs vanilla things.