I've not tried any other Canon LTM camera, but I do like my Canon P. It has everything you need, and nothing you don't (well, I do put a VC II meter on mine, though I keep intending to use a purpose-designed - and functional - Canon light meter I bought through RFF). I'm a ways from home for some months at present but when I get back I really want to try my Summaron 35mm/f3.5 in combination with the Canon P. I think that might be a very nice combination.
The framelines work for me at 35mm and 50mm (I've not used it with other focal lengths) - and while the RF patch isn't, well, a patch on something like a Leica M3 it is quite functional. The camera is solid in the hand, intuitive to use and I find it pretty to look at and nice to hold. Canon seem to have felt that film-theives were a big problem in the way they've secured opening the back - but it is still more convenient than loading my M3 (as used to that as I am).
I don't know what you want, but I think that a good-condition Canon P will always be a pretty good purchase.
...Mike