Both Vasari factions are OP in some way.  The VL can perform a strategy called strip-rushing in which they can hit 2000 fleet supply in 30 minutes, enough to steamroll anyone else early on.

The VR on the other hand are OP late-game.  Their specialized techs and mobile starbases (this in particular) make them OP.  Mobile Orkies are effectively psuedo-titans that cost no fleet supply and has the highest overall DPS of any "ship" in the game.

Not really, no.  Strip-rushing can't be countered unless you happen to have a straight shot for their homeworld and seize it immediately.  While possible, it's just not realistic.

As for the VR, if you don't kill them before they get a Kultorask and mobile Orkies, you're probably never going to.  Nano Leech+Gravity Pulse will eat your frigates alive and make the Kultorask invincible.  When they die, they leave behind debris which the Orky can eat to regen health as well.  There really isn't an effective strategy aside from spamming bombers, but all they have to do then is bring a couple Kortuls and they can ignore the bomber spam.

Definitely better then beta- but frankly their late game is still too strong- yes it comes late, but it's not like their early game is really substantially weaker then other races to compensate.  Honestly you can't balance a "once you get to late game this race wins" without a an equally subpar early-mid game(actually introducing too much superiority at any stage of the game is a bad idea to begin with).  The Vasari have always had what is likely by and large the strongest late game- the late rebel techs push it over the edge.

Also Nano-leech is still stupidly broken.