I've been here twice- on the weekend on both occasions. I'm pretty undecided as to how I feel about this place. My first visit here was fairly good, then my second visit was not so great.
I always order the large mango slush with tapioca. The first time I came, glass was overflowing with slush, which was a great thing. The second time I came, it was as if they decided to cheap out and just not even attempt to fill my glass. The servers are also not the greatest. You really have to flag the servers down in order to get any type of service. I don't think you should have to flag anyone down to get service- especially when it's not that busy for the night.
I can say that the endless flow of popcorn is definitely what makes me want to come back every time (I have a really unhealthy obsession with popcorn- especially if there's white cheddar powder all over it).
Another thing that kinda, sorta, really bugged me was the fact that my server stared me down while I was leaving my tip. I felt more inclined to leave less of a tip because she was waiting for something huge. I should've given her the tip not to stare. Oh well! I might be trying the other Grotto location instead. Great atmosphere though and the couches are a nice touch- and quite comfy! And the music is strangely calming. Oh! And power outlets for your electronics! Def a plus :D
P.S. be advised that they do not allow you to charge purchases to your card unless you've gone over $10. I learned that the hard way.