Just my two cents, I feel 219 is higher quality overall. It’s used very successfully on Tags which put out in excess of 27 HP. On the other hand, if you’re running 4 strokes, 35 is a better option. Most vendors who support 4 stroke events will have a variety of gears and chain for 35, not so much for 219. And of course, just the opposite for a 2 cycle race.
That being said, we run the highest quality 219 we can get on our Leopards, and RLV Xtreme on our 206’s. Never had an issue with the RLV product. It also breaks and goes back together very well with very little kinking.