The vasari have their starbase, remember. With the faster build times and better attack... then it becomes even more advisable to use their starbase as an offensive platform.
I'm REALLY concerned about exactly how the Vasari are supposed to use their SB to take out entrenched defenses including an enemy SB. Let's take the worst case:
Attacker: me, with a fleet
Defender: Vasari player with fully-upgraded combat starbase (3 weapon, 4 defense, 1 deflector), a phase stabilizer, and 25 points of static defenses (say, 5 hangars, 1 PJI, 3 missile turrets close to the planet)
How am I supposed to handle this? With a starbase? Okay, I bring in a colony ship with my fleet and immediately start to build my starbase. The defending SB moves towards my position.
Two minutes later, my starbase has finished completion. If, by some miracle, the partially-built SB survived two entire minutes of attack by a fully-upgraded defending SB (which probably reached the building SB within a minute), it's STILL outgunned by a huge margin (5:1 on offense, more like 8:1 on defense even before counting the deflector). Even adding the disintegration beam only narrows the offensive gap to something like 2.5:1 or 3:1. Making the disintegration use the anti-structure weapon class goes a ways towards balancing the offense a bit more, but it does nothing for the defense. Giving it enough upgrades to survive a direct confrontation with a defending SB, even with fleet support, would take several more minutes (since none of the other upgrades had their times reduced). And again, in the meantime it's being destroyed by the defending SB. In other words, the SB was useless for taking out the defending SB, and my fleet had to take it out themselves. Except whoops, ship-vs-SB damage was nerfed in this patch, so it takes a larger fleet than it used to to outgun a starbase.
So that's the worst case. Let's take the not-so-worst, where the defender is a Terran or Advent player. In these cases, you'll have time to upgrade the SB before going in since the defender's base can't move out to engage you. It's still two minutes to build, and even with the reduction to 25s for the first weapon upgrade, you'll still have a base that doesn't have a prayer of survival against a fully-built defending base. So you'll HAVE to sit there on the edge of the well, with a fleet defending your in-progress base, for a good TEN MINUTES until you have a base capable of standing toe-to-toe with a defending base. Or, go in without it, in which case we're right back where we started, with the nerf to ship damage vs. modules.
You'll be able to use a partially-built starbase to draw fire away from your fleet, and help with the damage a bit, but this is a LONG way, balance-wise, from a purely stand-off weapon like the torpedo cruisers that can destroy a defending SB practically unassisted.
So to me, there are a few ways to fix this.
1> In 2.5 the build times for starbases were changed to depend on the ownership of the well, with enemy wells taking much longer than friendly. This change needs to be removed for the Vasari, so that they can get their offensive starbases up and running quickly. Or, to keep it balanced, INVERT it. Make Vasari SBs build the fastest in enemy wells, and slowest in friendly wells. It doesn't have to make sense... it'd just be balanced.
2> Vasari starbase upgrades, especially the core offense/defense ones, should build much more quickly, even if you have to raise their costs to balance. What if, instead of 1800/275/150 and 60 seconds, they were 2700/425/225 and 30 seconds? Now, I might only have to babysit the growing Vasari SB for 3-4 minutes before it's ready to smash the defenses for me, but it's more of a financial commitment to do so. (Maybe have this cost/time change only apply in enemy wells?)