I've read online that there really isn't much difference in quality between the s2 and se. If you. or someone else that has tried both could clarify what the improvements are that would be appreciated. If there are no difference, do you think that just buying a SE and upgrading PUPs would be a good idea. Is there any tone difference between the 22 and 24, or is it just neck width. Finally I might just be patient and look for a used core 22/24 and pay the extra grand or so, but opinions and recommendations could really change my opinion.
Well, look at it this way: the SE line is a great relatively-inexpensive line of guitars that have al the classic PRS characteristics, but with some small, unnoticeable-to-some compromises to help cut costs. The S2 is going to have slightly better quality in those areas (such as locking tuners), while still not hitting the full quality of the Core line - pickups in the S2 are one of the areas that are often touted as being the biggest weakness vs the Core models.
Of course, the other aesthetic differences are that the Core models will have a figured maple top that is figured all the way through, whereas the S2 will have an unfigured top, and the SEs will have an unfigured top with a very thin veneer of figured maple on top to give it that "pop". IMHO I wouldn't let aesthetics drive your price/model range, I would let the features do that first.
I have four SEs and four Core models, and I love them all - I was playing my SE-7 and SE Baritone yesterday.
So if you can, go to a guitar store that at least has some SE models, maybe an S2 or three, and maybe a used Core model if they don't carry the line new. And try them out. You'll quickly decide what you like or don't.
Oh, and as to the differences in a 24-fret and a 22-fret model: the relative position of the neck pickup changes which can affect how the strings are picked up (but neither is better or worse, and the difference is mostly subtle), and of course it will feel a bit different (the 24 fret version will have a longer neck and balance ever so slightly differently). Neck width is no different (unless you get a different neck
profile, but that has nothing to do with # of frets).