EF Yak and I believe the Showtime 4D have airfoiled tail group. I remember hearing that from the best flyer at our field,he said the best way to go was a 3-D plane with airfoiled tail group,which I promptly followed his advice with the EF Yak,pretty light for 68" wing(9lbs) with Saito 1.50,I couldn't hover that *itch for a few seconds even after pushing the engine out like they said. I added tons of up-thrust to no avail. But then again it took me 3 years of tryi ng to get into the groove with a Do,first I had to learn what the plane needed to hover easier/better-usually up-thrust,more right thrust,I had to figure out what was the best prop/engine combo,fine tune the prop to allow more "slippage" downward,better throttle response,then I still needed to fly more to get my first tail touch and I need to do it when its light wind or it drifts too much. All this without a sim or foamy to help. This is the hardest thing to do in 3-D IMO,especially when TR'ing,actually it may be the hardest thing to do period, with a model plane. If you can afford it,get a good sim,a foamy,pal around with a good 3-D flyer and buy a known good 3-D plane,then you still have to burn a lot of fuel.