I just ran Vateshran Hollows for the first couple of times on Normal. It wasn't too bad and I enjoyed figuring out the mechanic-heavy fights.
The only fight that was frustrating was the final boss in the green zone. I did that zone last (I did Blue > Red > Green) and while the fight wasn't hard, it took almost as long as the rest of the dungeon combined.
Once the minotaur got to the point where he was changing colors, I couldn't get him to change platforms so I could damage him. And when he finally did change platforms, he would switch to the color of that platform immediately, becoming invulnerable again.
I probably cycled through "interrupt the summoners" phase 12 times before finally killing the boss. I'd be on a blue platform. He'd jump over and immediately turn blue. I'd change platforms and he would just stay on that one shooting fire at me. Forever. Eventually, he'd jump to red but immediately turn red. I'd grapple to blue and he would stay on red forever, shooting fireballs at me. This went on for ages.
What's the trick? Should I stay on the plantform while he's invulnerable and wait him out?