The .50's would be marginal for 3d at elevation, but in Texas, I imagine your elevation is a lot lower and guys that use the 50-size 2 strokes work fine. An OS55AX seems to be a popular choice, largely because it will swing a fairly large prop. I wasn't a big fan of profiles either, but after I gave my damaged Reactor to rcplanenut, I got an Extreme Flight Chinn Yak and transfered my gear to it. Definitlely better power to weightmy Reactor was 5.5 pounds, and the Yak is 4.5. Gotta say the profile will do more tight, twisty 3D stuff (it does this incredibly tight knife edge spin), but the Reactor will do some of that and definitely is more precise. I still really like the Reactor, and it sounds like you might be interested in something like it. That UcanDo sounds pretty good too...