I just got the Pursuit, I was down to the same two models as you. The pursuit is a great unit. Very simple to use, very intuitive functionality, the backlight is automatic, so as soon as ambient light drops, it turns on. Batteries are user replaceable and is done very easily. Batteries are designed to last at least a year, even w/ the auto backlight. It does not have standard buttons, it has piezo buttons so there really aren't any moving parts to break. They are more like the contacts on a uwatec BT. I am getting comfortable w/ the GF algorithm. I really like being able to adjust the algo to suit to the dive, and it is much easier to do than w/ V-planner (may be a factor of my ignorance of the model, but I am not comfortable screwing around w/ critical nuclei, etc.). Word is that Bruce is working on running V-planner live on the unit, but no commitment yet. When it came down to it, here were my reasons to go w/ the Pursuit:
1) User-replaceable batteries. I know, I know, the X1 now has a battery policy but if it goes (and I have read about a few that have)- it goes back to the factory. Not an option for me. I want as much of my gear to be field serviceable as possible.
2) Breather-compatible. I'm looking at going close circuit in the next year or two and I have my sights on the rEvo. The Pursuit is plug and play with the unit, and reads three cells. It is also upgradeable to the controller used in the eCCR version of the rEvo.
3) Reliability. I have never heard of a problem w/ a Pursuit. I have heard nothing but rave reviews for them. The unit is an evolution of the previous model (Shearwater GF) so it is an improvement on an already solid unit, not brand new technology. I've seen enough reports of issues w/ the X1 to give me pause, which pretty much made the decision for me. I'm not knocking the X1 and I have read nothing but great feedback on their service and support, I just prefer to have something that doesn't need service or support
4) Cost was more of an additional benefit. I was able to get a pursuit for quite a bit less than the X1. This wasn't a deciding factor, but made it an easier decision.
Cons:
1) Size- the Pursuit is just a little bit bigger than a VR3. Not too big, but much bigger than the X1
2) Algorithm. I prefer VPM, but am really starting to like GF. More flexibility than VPM, but not a true bubble model
3) I really like the OLED display of the X1. The Pursuit is fine, big and bright enough for me, but pales in comparison to the X1.