People that keep saying "get an OS21, Picco26RD, RBTM23..." are people that aren't looking at spending $100 more than they have to to get an engine that has enough power to do the job and do it well.
With a little care and an aftermarket con-rod, the 3.3 is a decent screamer of an engine. Spending $200+ when you don't have to is just silly.
I have an LRP28S3 in my revo. All I can say is, it's a PITA to drive. Probably would have just as much fun at much less expense if I put an engine in the thing that was the right engine for it.
I'll never say the TRX2.5 should have been put in any MT. But the 3.3 is a decent performing engine, short of the con-rod issues.