There are a lot of reviews of YCs and they seem to be pretty accurate but I will throw my opinion into the mix. YCs is a really fun place. All of the employees seem to really like working there and they are always exceptionally friendly.
The food portions are enormous if you pack it down into your bowl (I recommend doing son). Get a small bowl on the side for your sauce (you don't have to fit that into your mess of veggies and meat)! and that makes everything a lot easier.
As for flavor I think it's pretty good. I don't recommend going off in your own direction on the sauce, follow their recipes. Every time I've done one on my own it hasn't been as good.
If you like this concept though and want more for taste then go to Genghis Grill. The portion is slightly smaller but the taste is much better.