I recently visited Heist with a few colleagues for a Sunday Brunch celebration! We had worked a 300 person wedding the night before and thought we earned a hearty meal and a few drinks. I'm going to rate the value/food a 5, and the service/experience a 3, so rounding out to a 4.
The seating/reservation process was slightly confusing and ultimately it took us about 20 minutes to be seated (even though there were 6-8 tables in server's sections that weren't being used). This was after I spent 20 minutes literally stalking every person who left the building to try to grab their parking spot. Parking at this place is horrendous when it's busy.
Once we were seated, things went slightly more smoothly. I think that the waiter was overwhelmed and had too many tables, because it took quite a long time to get our drinks and subsequent refills. Often times we had to flag him down as he was running back and forth. However, since it was a buffet, we never had to wait for food so that was nice.
The value of the experience was definitely worth the price point of the buffet. I liked that you got to choose an a la carte option from the menu in addition to the buffet. I also liked the waffles (you have to request them from your server, but they were a hit).
Overall, once you can find parking and get a seat, things are good. I had a great peach bellini with my meal and my colleagues shared a mimosa pitcher. The pitcher itself was an odd shape and it kept spilling when they poured, but that could have also been the tipsiness.. : )