I'm happy with 2 stroke or 4 stroke, it all depends on the application.

Who would really want to refine a scratch build Platt warbird and then stick a 2 stroke on it to ruin the effect losing scale sound? I like my 4 strokes and never had a problem with any OS or Saito 4 stroke in the last 9 years I became active again in the hobby. Not one. They run like a swiss watch, smooth idle, and just sound very scale, with a lot more torque than any 2 stroke I've owned. Great in biplanes, warbirds, and slow moving heavy planes, 4 stroke is their home.

For speed, I like the 2 stroke. For cost, I like the 2 stroke when it's a $99 knock around Sunday flier.

I avoid the YS engines due to the 20/20 fuel they want for smooth idle and transition. They are very thirsty too. I would hate out of habit ruining the seals on one if I accidentally threw after run oil in a YS after flying.

Some cowls are tight and the 4 stroke muffler doesn't require as much cutting.
Some cowls are wide, and a 2 stroke fits inside best with a deflector sticking out of the bottom.

Some planes require a lot nose weight to balance, so a 4 stroke will add that 4 ounces for you without static dead lead.

I just go with the flow, whatever fits the application, it's all good. I just got into gas, so I have little opinion on that until I get more acquainted with them. It's really the only 1/4 scale reasonable option, clean up is a breeze, and again, it's all about the application.