I suspect (though can't prove) that the Bravo's are all the same circuit, with a different heater setup for the different tubes, and an EQ for the V3. I have variously heard some people proclaim the V2 to be better than the V1, and others say that 6922 tubes are better than 12AU7's (also something I have no clue about). Still others buy the Ocean and proclaim it best (maybe because they paid more for it?)
In my brief experience, I have found the 12AU7's and its variants to be (mostly) less expensive than the 6922's, but that could just be chalked up to random chance on eBay. I suppose like a lot of other things in this hobby, that's an entirely subjective observation. I like cheap, so I went with the V2.
Personally, I'm not going to be buying a V1 or a V3 to find out which is best. I did toy with the idea of buying a V1 before I bought my second V2, but decided against it. The real reason I wanted two V2's was spare parts, lol. Just in case one of them blows up, or I goof up one of them when I finally get around to modding. Or in case the PS takes a dump, etc. In retrospect, I probably should have gone for something different. On the bright side, at least it wasn't an expensive mistake.
AFAIK the only difference between the V1 and V2 are the tubes familys. Generally speaking 6 series tubes are more expensive, i cant speak for which sounds better as i've only ever used the 12 series.
The same basic circuit was used in amps made by Indeed and Little-Bear, the latest versions of each have a switch to select between 6 and 12 series of tubes opening up a lot more options. (Indeed G2 / Little-Bear P-1). The P-1 was being auctioned off on ebay recently, i picked one up for $20. The latest version of these amps is currently the Indeed G3, though i expect Little-Bear will release their version shortly.