jeff, have you spent a reasonable amount of time on a well setup boosted 4 stroke? There is honestly no scenario where I would rather have my turbo etec over either of my 4 strokes.Pouring 2 smoke oil in???
I don't touch my oil for 3 tanks of fuel lol, and I have seen nitros with oil topped up every ride so that is nill and void
Belts is also a non issue ( at least for doo)
Engines, also a non issue for doo now as lots of etech with 10000 plus km on them
I still think for anything other than straight chute machine, a boosted 2 smoke is the best all around machine