Yeah stock Glock basepads are horrible to remove. I think it's idiot proofing for LEO. Swap to aftermarket basepads if you shoot it enough to need cleaning or spring replacement.
I had a Cajun kit in my p07 while I owned it. Definitely nicer than the stock omega trigger. I did up an old SP01 in a full Cajun kit when it was my backup uspsa gun and it was probably 70% as nice as my AccuShadow in regards to the trigger.
I typically use ISMI springs in all my pistols, but have used Wolff in the past with zero issues.
Find the right weight to run with your preferred ammo and you'll be humming right along.
I had a few different aftermarket connectors that wouldn't work with mine. The OEM minus (-) connector seems to work fine with it.
I've also seen people fail to get the screw in the bottom of the housing all the way in and that cause problems.
I installed several of their kits back when I ran CZs for competition. Most were purely drop in replacements. There may be some very minor polishing required.
It doesn't completely harden like loctite does. Typically when people breakoff the heads of optic screws it's b/c of the torque required to break loctite free.
The only thing I use it for is slide ride pistol dots.
I just got done dealing with all sorts of feed issues in the mkIV I use for steel challenge.
It's really a combination of things. Springs, polish the inside of the mag, run a little oil down the front, and different ammo. Finally it ran without issue last match.