my first plane was a SIG LT-40 kit, and my second plane was a Hanger 9 F-22 ARF.

I did not take a single thing out of the LT-40 to get the F-22 in the air.

I even installed the flap servos from the start.

I then got a T-Rex 450 to try my hand at helis. to get that up and running I needed a new radio as my "old" futaba 6 channel computer radio would not do the correct swash mixing. So I got a DX7 that now controls all of my planes.

My next plane will be a SIG Hog Biplane with all new equipment.

So in the end, I don't see having a plane require more servos or a little more advanced radios to run them as most people will buy additional equipment to keep their old planes in the air. This gives people more options at the field.

I personally think a second plane should be more advanced than the firts plane, both in capabilities and setup.

Now on topic, the F-22 has a 55ax in it, and it flies that brick of a plane great. The LT-40 have a super tigre 40, and that thing runs great as well. The super tigre I bought for $25 (clearance at a hobbie shop closing its doors) and the 55ax was well over a hundred. Both engines are very reliable, but the 55 has at least twice the power. There is now way I would put a super tigre on a "performance" plane, but I would think of putting the OS on a slow flier.