Which jet should I go for?

I read something about changing how the booster works, supposedly it was nerfed. Something about losing the 2-stage booster and instead having just 1 second more of the normal booster when compared to r77. Could be wrong.

That one second more of burn gives it 20% more delta V compared to the standard r77

Yes naturally. I’m talking about current r-77-1 vs its initial version.

The delta V did not change as far as I am aware

So I guess my plan is to have fun with the yak141 till I unlock the 30sm