I'm not usually one of the first people to update, either, lave. I tend to many of the same worries. What if the game just doesn't fly the same after a change and all your practice in getting good at certain moves suddenly becomes nothing but newbie flailing again? What if an OXP isn't supported and it was one you rather counted on? What if things just don't "look right" anymore? It *is* worrisome. All I can say is that so far, i personally have usually found the changes for the better to outweigh any bits that are lost.
Going through and updating the OXPs to newer versions is a bit of a hassle. But you do see a list when you start Oolite that tells you which ones are having a problem, and it's nowhere near all of them, just a percentage. So that isn't likely to actually take days or anything, maybe an hour or so. If you customise OXPs a bit sometimes, yes that can add to the hassle. I have two separate "characters" that pretty much live in different Ooniverses, since the OXPs installed for each are quite different, and while both are modified at least a bit, one has a fair number of modifications/tweaks. I have taken to keeping a TXT file of any changes I make, so I have something to work with when a necessary OXP update means I'll have to decide if I'm going to go through and make those changes again. I won't say that solves all the problems involved, but it can help some.
I also keep the install files for Oolite, so I still have the version of the game itself that "used to work right" in a folder somewhere, just in case. That's more of a remedy than a cure, though, since you can revert to the version that worked with what you want, but you also will miss out on some of the new developments you might like. You end up having to make hard choices. One of my "characters", for instance, is sort of stuck with an older version of Oolite because aesthetically speaking, he's not the sort that would care to stay (as in dock and save for the night) at a main station. The "Save Anywhere" OXP is a hard one to give up there, since "the game in the head" for me sort of fits much better with that character ending and starting a play session on planet surfaces or pretty much anywhere *but* a Galcop main station. It's not so much that the game is somewhat brutally biased in favour of a "non-fugitive" status, since he is almost always "clean", as that the character has as little to do with Galcop as possible. LOL But that also means that when I play that character, a lot of the nifty new stuff just won't work.
Even in my "main" character, where that isn't so much of a necessity, there's other problems. My keyconfig is modified quite a bit, since I use a modified keyboard as a "control panel".
Just about every time I think I have it all worked out and settled to my liking, there's an update and some keys get changed or a neat new one gets added or more controls are added under the joystick possibilities, so I can move their functionality to a different controller and use less keyboard. But that project is kind of "lunatic fringe" anyway, and such changes aren't a hassle for most players. It's a case where I wanted something weird and so I end up having to do extra work if I want to keep it working and up-to-date.
Back to the point, I understand the worry, lave. But there's a lot to miss with not at least trying the major updates. If you don't throw away installation files of versions that have worked well, document any changes or tweaks to OXPs as you make them, and consider maybe having more than one Oolite on your machine so you can at least try the new things without risking messing up the old ones, then at least you can have the capability for making an informed choice at the cost of it being a bit more work.
<with unbounded joy>