I've been flying a 3 blade setup on a Protos Max for a few weeks and I'm eating crow. I love flying the thing.
Compared to a 2 blade it has more gyroscopic effect, so has more of a locked in feeling through maneuvers. It's less natural feeling and quite a bit more robotic. The visual effect is quite dramatic.
For harder flights, I run it at 1950, where with a 2 blade I usually run 2150. So the flight times between he 2 setups is about the same.
The 3 blade setup autos ok but for sure is worse than a 2 blade setup. The model won't recover headspeed as easily, and he additional parasitic drag with the third blade hurts. Still fine at dismount style autos etc. But tumbling autos are challenging.
Because it runs at lower headspeeds, you either need to increase the tail ratio or go to a 3 blade tail. The three blade tail is ideal since the sound is awesome, and the mechanics spin at lower speeds, so it's less vibration and performs insanely well.
I ate crow on this as until I really started flying one regularly the ones I had tried didn't impress me. But once I had my own and really tuned it I really got hooked.
It's a new fun experience in helis. It's different. Has a neat feel. Has some tradeoffs. But for sure is a fun thing to play with in the hobby.
MSH USA -- Cyclone -- Jeti -- Xnova