Got my V3's in today, did a quick A/B but so far the V3 fixes the harshness/timbre of the treble. I can listen to pretty much any track on these at high volume with no fatigue compared to my V2. As already noted, the bass is also much more noticeable and full, packs much more of a punch/impact but doesn't feel bloated or bleed into the mids/highs at all. I'd say it's pretty close though to being a bit too much for my tastes personally.
The soundstage doesn't seem as large as the V2 and the sound for sure does sound closer to you compared to the V2, but I wouldn't say it's a massive difference. It's by no means intimate though, I've used HD600's for years as my main headphone so I know that sound very well.
Will do some more testing, but I think the claims of the V3 being a disaster are heavily overblown. The V3 sounds more natural for all kinds of music. Games and movies also are more enjoyable on the V3. I do admit though I like the V2 more than the V3 though on certain tracks, there isn't as much air in the treble with the V3 and with a well mastered song, I prefer the treble presentation on the V2. Going to be tough to choose between the V2 and V3 though.