One other small item 4 strokes have in their favor is since they run lower RPMs, they tend to be easier on glo plugs. It's not uncommon to go several seasons on a single plug. I've never been able to get a 2 stroke plug to last beyond the first set of weather changes (and some tweaking). These were good plugs also solid platinum elements OS A3 and F plugs.

On the flip side, the 4 strokes DO vibrate more and this often shows up as tank foaming or fuselage integrity issues, so that needs to be dealt with properly.

Each has it's charms. When you see a good pilot flying his favorite setup, you can't really tell the difference except for the sound.