Bigger engines are NOT easier to run, IMHO.  This is especially true of the 2 cycle engines.

"With great power comes great responsibility"

In other words, you only need so much HP to fly an airplane of a given weight and drag , the rest is just reserve, the more reserve the more trouble you can get into.

The 4 strokes take to being "choked down" better than a 2 cycle, also.  A 2 cycle is a very heat critical animal.  Choke down a big 2 cycle motor, it has trouble staying lit.  This forces the need to run bigger props, which creates more GP, blah blah blah...  Unless the bigger engine is just gutless, then the added displacement does nothing.

On the bigger 4 cycles it was possible to venturi down the engine and get a smaller engine "like" response.  It did not find this to be true on the larger 2 cycle engines.  So much is put into the "SOUND" of a 4-2 run....

All this being said, I really look forward to someone proving me wrong!!!  I think the increased engine displacement rule is GREAT!!!