AhKay,
I know your researching the hell out of chassis, I see you on a bunch of threads, but you may be doing so much your head will implode. First, on chassis, you need to get behind one for a while and not just some dry fire or a range trip. A chassis is a different shooting platform and some love them (me) others hate them (bohem) so it is 100% subjective. I don't know if there is a direct correlation between time with pistols/ARs and comfort of a chassis. Perhaps there is because I did not go to sniper school until I was 40 and had been carrying an AR/pistol in the MArines/Army and PD for 22 years. I was never comfortable with the HS stock I started with and at sniper school shot a guys McRees and it felt great. I have been a chassis guy from that point on but I have also run Manners GAT and McMillan A4 and really liked both but still prefer the chassis.
Now onto the comparison. Disclaimer, my kids are all grown up, house paid for and I am well employed so I spend money on my two vices, powerlifting/bodybuilding and rifles. For that reason I don't mind losing a few bucks and buying something, using it and then selling it. For that reason I have a collection of chassis; see photos below. WHat I have used is; AICS, McRee, XLR, KRG X-Ray, Knoxx Axiom and the JP.
I enjoyed all of them and they all have advantages but my preferences are in the following order from favorite to least favorite: X-Ray, XLR, AICS, McRee, JP and the Axiom. Now "my" preferences differ form others but the X-Ray wins hands down because of one factor, weight. The thing is like 3 pounds. Hell I have heavier bowel movements, and it is as comfortable as any chassis I have used. Weight is a factor when you need to shoot standing unsupported or even kneeling or seated. Also makes a difference when you need to lug stuff around, but most shooters go from the parking lot to the firing range so that may not be a factor. The ergonomics of the grip fit me very well and there is a nice space for my thumb. It is adjustable but you do need the spacers for the LOP but even when I go from heavy TAC gear to a t-shirt I don't find a huge deviance. Must just be my build but once I set a chassis LOP I almost never fiddle with it.
XLR is just a excellent piece of work. Yes you need a tool to set it up but once set it feels great in the hand. It is lighter then the others, but not as light as the X-Ray and is a tick more in price. The nice thing is Kyle can fit an XLR to about any rifle and mine sits on a Howa 1500 and another on a FN SPR. It is adjustable and like all chassis allow the use of rails all over. I use them, mostly for "work" and like the ability to attach my NVS, lasers, lights, flush cups.... but if you don't need them the tube is fine with no attachments.
AICS is great and I will not sell min. I will swap it out with the X-Ray form time to time but its a keeper. If I never used the X-Ray this would be neck and neck with the XLR. Down side, it is a slug to carry around. Add the IMUNS and a bipod and unsupported positions take on a whole new workout aspect. Also no real place to add flush cups or rails other then the IMUNS (or adding Viper skins, an excellent addition) Still a great system.
McRees, same as AICS, heavy. Great chassis and lots of options at a good price. Had one, used it, liked it but sold it off. No reason not to get one but for me I more or less like the "look" of the AICS and XLR and when the performance is the same it was more aesthetic then anything else. Still a great looking rig but the whole eye of the beholder thing...
The JP I just didn't feel good behind. I can't even articulate it. Some people love them, I just didn't get that fuzzy internal feeling with it. Ditched it quick so not a lot to say.
The Axiom was not bad once a made a little modification. After the first few range trips I found all the recoil absorbing springs in the stock and pistol grip seemed to change the travel of the rifle on recoil. Again, can't articulate it but IT SUCKED and threw me off. So, I took a punch and tapped out the springs. Then it was just a chassis and was actually a solid piece of work. It shot well and I enjoyed it for the price... free. I went to a Blackhawk class and they reps were pushing them and one of the guys tossed me one. Got a bit of use out of it but it was not really in the same league as the others. If you come across one for $100 or less, tap out the silly recoil absorbing springs (side bar, is the .308 really that bad that we need recoil absorption?)
As for accuracy, what I can say is there was really no difference in any of them. Well the Axiom sucked till I took the springs out but then it went back to 1/2 MOA. All were at one time or another on my best 700 but float around my other rifle as well. So it comes down to preference and little things like weight, attachment points, price and looks. Bottom line I can't see you being totally dissatisfied with any of the chassis out there. You may find a better "fit" over time but I would make sure its what you want and pick one and shoot the hell out of it. If you don't like it throw it in the sale section here, or hell I'll I may buy it, lol.
Sully