I have shot a full size 1911 and I own/carry a Pro Carry II. I really can't tell much difference between the recoil or accuracy of the two. I did replace the factory spring with a Wolff XP spring (part # 32725) as it is recommended over the factory one. The 4" will probably have a full length guide rod and bushingless barrel and the 5" doesn't. The take down will be different, but to me the 4" is easier and quicker...you just have to use the supplied recoil spring capture tool (which looks like a bent paper clip
If you get the aluminum alloy frame/stainless slide version, it is recommended that you use a plastic skirted follower magazine so it will not scratch the inside. Otherwise, regular metal follower mags work fine.
Good luck with your decision and enjoy whichever one you decide on.
Personally, I like the shorter version, but that's just my opinion.