The Ramp Crabs are awesome. For the average joe, it's overkill and a waste of money. Almost anything is better than an scx24/ax24 servo. Same thing. Trim the ears of the Emax. No interference on the trx4m. Slight interference on the scx24. Cost and performance wise, I can live with it. Love this...
The Emax servos get a lot of praise as well. Have one in my trx4m tarantula build. No issues. I wanted to try the Ecopower when I ordered my scx24 from Amain but, like you said, back ordered. Just grabbed another Emax from Injora. Along with the mount. Doing great.