Za's has probably has location as the best thing going for them. They aren't expensive.. but they aren't dirt cheap considering what type of food they are giving you. You have your choice of salad, sandwich (I don't say panini because it's not), personal pizza, or pasta. Lots of options I suppose... but the quality is questionable. The sandwich and pasta are okay.. but if you get a salad.. it's not very well mixed and they really don't give you much for toppings (you have to pay extra for any type of meat). Also I got massively sick from their soup once.. particularly their clam chowder which I suspect had rotten clams. So.. no soup for me anymore. Oh.. and they also have desserts shipped from Cheesecake Factory, etc.
The tables are always a little dirty with crumbs, oil, etc. So that's something I don't like. Yes, there are a lot of people who go here.. and so the waiting area to pick up your food is a little crowded. Also the long stairwell to go upstairs for additional seating stinks really badly. I think it's because it's carpeted and the garbage is there.. so it is just gross.
Honestly I would rather go somewhere else on Green Street if I really wanted something to eat. None of the food is too special or anything you can't make yourself at home for 1/10 of the price. But it is a place that is easy for a big group of people.