For me a detachable magazine is simply a convenience. I'm comfortable with it and prefer it. There is nothing convenient about having to load rounds through an open bolt. Also not having to get up from a prone position and reload after every four rounds is a convenience thing.
I tried a conventional stock and magazine and I didn't like it. Of course my first rifle was an M-16. It's a lot like a manual versus automatic transmission. I can use either, but I prefer the automatic.
regarding the compatability thing. It's a not there yet. Even my AI mag took two tries to get the right one. Both from AI, both 308, both 10 rounds. First one didn't fit. I didn't have them at same time to compare for differences.
Experience is a very bad teacher because it first gives you the test and then teaches you the lesson.