A few impressions from day one:
1) Fountain V3 arrived today. Two negatives right off the bat: schitzoid wolf graphic
and smaller ID top cap.
Currently soaking...
2) Vaping great. Stock side air holes are a tad airy for me, but close enough. Spit back guard smooths the vapor nicely. The velocity posts are great to build on of course, though the juice well is smaller and shallower than V2. New squonk section holds a bit more than V2's bottle, about 1.5 ml more, and the squonk action is nicer due to the softer more elastic material compared to the bottle's polyethylene.
So far so good performance-wise. The smaller top cap ID pisses me off though. Can't just throw on the stock or custom tops from the V2. On the plus side, the built in drip tip ID fits standard 510s, so I can cut it off and replace with SS or Delrin if I want.
3) Getting some especially great flavor from the V3. Positioned the coils high so the air hits the bottom of the coils and goes around them more thoroughly. No center post in the way. At least that's why I think the flavor is improved. YMMV.