I reviewed my question, again, and thought it may be too broad. What I'm trying to get a handle on is what the difference is, if any, regarding the sonic signature.
There was a very good review of the P5 in S'phile I think, when the P5 came out. The reviewer compared it to the P25. Hopefully you can look up that review online.
But, what's the price diff. between used P5's & P25's? $200, $400? The P25 is a very good TT. You can upgrade your cartridge & phono stage around it to a very high level. Personally I'd go with whichever I found a deal on, used, & if a P25 is a lot less, you can spend the $$ saved on a nicer cartridge, which I'm guessing will make a bigger difference.
You can't go wrong with either, but if it's only a couple hundred $$, I'd go with a P5.