I have a Revo on a 0.1 so some apples/oranges here but generally I do like it. I didn't build the V0 for speedboats so I do run on the slower side (it mostly prints ABS as well). Nozzle changes are decent on the Revo but I haven't yet setup the end of print retraction so I can easily swap nozzles without having to heat the nozzle up, retract, cool it down, swap nozzles then heat it back up.
Other minor gripe is I've had a bit of filament get broken off at the very top of the nozzle assembly a few times which is initially hard to figure out (and requires removing the nozzle to realize). Some (all?) of the Phaetus hotends have single hand nozzle changes. To me based on having to heat/cool, I think I'd prefer that over the Revo method.
Final gripe, no nickel/copper nozzles. Their fancy Obsidian or whatever sounds nice but it's more than I need/want. I don't need a fancy coating or anything. Feels over-engineered when I have a solution I really really like already. I get such good quality with the nickel/copper nozzles on my MK3s and don't want something more complicated than it needs to be. So I'm hoping they offer those at some point. I forgot how sticky brass is.
On no wait final final gripe, it isn't fully open source and I don't like the trend printer companies are moving towards.
I do have an open post on the V0 forums about a possible issue with the heater but I'm not yet sure if that's actually the Revo. If it is, I expect E3D would replace the failing parts without question. They're a good company and while I really don't like some of the closed source bits, I tend to blame Slice more for starting that recent trend, but still do wish they opened up this design. If they had, I would've probably been converting my Prusa's over as right now I just have reservations about spending more on the closed ecosystem.
Some negatives there yes but overall it's performed very well. I know some folks dog the heater design as being less efficient but I do find it does seem to heat up really fast. Fast enough to start extruding plastic anyway. It does indeed feel much faster than V6 and, at least when my V0 isn't giving me issues, prints are just fantastic.
All that said, for V4 I'll start with the Dragonfly as that's what my V0 came with and I'll see how that goes before I decide if I need a Revo or something else.