No-one said GO are the best...but
-will last long
-perform great as long as you get the right one for your application
-and they do try to fix there problems with the carbs
Others throw it at the tunner/driver if something goes wrong with there engine...see "high end engine" own forums!!

In off road a lot of things can go wrong...
-your air filter might go off
-a runaway

I don't even want to imagine this with a >$300 engine.
Do you want to discuss parts availability and cost...i don't think so.
RB/Novarossi rods are $50-$60
Picco-i saw somewhere they charged $78 for a rod.