I don't see it favors big servers as if they are "servebots", they usually don't get to break easily, hence just hastening to a TB which they could still lose. I think fast tactical players get an advantage on this as just get one break and you virtually win the Set. The difference now is you need 3 Sets to win it but you don't need to think two times how to break your opponent to win the Set. That being said no-ad and no-let is not really fun (although let-fault seems interesting where touching anywhere but the service box is considered a fault) in a long run. For quick tennis matches it seems cool though.