Wilson Watt Puppy, which version?

I am thinking of getting into the WIlson line with the Watt Puppy's. I have heard a few before in showrooms and I enjoyed them. I can not afford a new one, so looking at the previous ones there were several versions produced over the years. Can anyone explain the differences and if there are any "sweet spots" in the line up. ie is every newer version better or was there a point of diminishing return with the introduction of newer versions? I am trying to stay under 10k for a used pair. Thank you
I never liked any of them until the 6 and 7. To my ears, the 3/2 was a painful listen and the 5.1 wasn't much better. Things changed with the 6 and 7 which are two of the best speakers I have ever heard. In my opinion the 8 was a step backwards and, if memory serves, it didn't stay in production as long as the others. I actually prefer the iterations of the Sophia. Good luck with your search.

Vdosc...I would go with a Sophia 2. They are easier to drive and probably a better match for your ARC VT100 Mk II than the Watt Puppies. You should be able to get a used Sophia 2 under $10K.
I agree with Narrod. I think that up until the Sasha, the 7 was the best Watt Puppy.
IME, lot of folks (not just those above) like the 7 best of the W/P lineage. I have somewhat limited experience with the progression of the WATT/Puppy, but off my auditioning, I'd agree with that assessment. IMO, that conclusion also squares with a general preference for the Sophia in that the earlier W/P versions always struck me as slightly lean, until the 7s which are IMO a bit fuller in the mid/upper bass. The Sophias (particularly the original) sounded fuller yet. The later Sophias and the W/P 7 seem to converge on an octave to octave balance that works for a lot of folks.

Caveat: Above conclusion qualified for limited auditioning at different dealers, different systems, and different times - so a big FWIW.

Good Luck

I have owned several Wilson speakers over the years, all but one pair was purchased used. I actually like the 5.1s better than the 6s but not as much as the 7s. Maybe it was the set-up of my system versus the systems I listened to the 6s in.

I do not like the Sophia 1 or 2s as much as the W/P series, but that is a personal preference. I find the Sophia's to be a kindler, gentler Wilson speaker - sort of like taking one 75% of the way into the Wilson House sound, but leaving some "forgiveness" in the speaker. In my opinion, the Sophia is a transitioning speaker to the Wilson house sound in this manner. Don't get me wrong, it/they are very good speakers, but for me that did not deliver enough of what I like most about Wilson speakers.

Price wise, the 5s are the proverbial "bargain" in the Wilson line up. I would not trade out my 5s for 6s straight out (unless my plan was to sell the 6s for more $ and buy the 7s).

All this is said based on personal preferences and my preferences may (probably) not match others. I find that one must be willing to spend some time setting up the Wilson speakers to get the best sound, and to be honest, doing this with the Sophia's is easier (mostly because they are a single piece speaker and also IME a bit more forgiving).

I think the key is to listen to them, and in more than just one system. If you are listening at somebody's house, you need to determine what that persons goals are with the speakers - as they may not match yours and therefore set-up for different goals and objectives. It is also extremely important to note the amp and preamp used - the W/P are very responsive to changes in components, cables, etc. . . Again, recognizing the owners objectives or performance goals.

Finally, unless you like/want detailed sound I would not buy Wilson W/P speakers. To me, there is little point in buying them and then using all sorts of other components that are just going to soften them up/down. I like Wilson matched with neutral (not overly warm) amps. If you want rolled off highs, buy a different brand of speaker, IMO. Buying W/P and overly doing this with the other components is counter productive in my mind.