Went today, they are on houston and macdougal and have a restaurant portion and a take out portion (no seats, though there is a place to stand and eat). The take-out section seems to be the kitchen for the restaurant so it is kind of hectic. I got a slice of regular at the take-out part ($2.50). We can get into the quality of the slice (see below) but most importantly I don't think this is even an attempt at the DiFara's slice: the sicilian slice is made with meat-less sauce, there is no pour of olive oil, and it seemed like there was only one type of cheese used. [I did see them making a whole pie and it looked like they poured olive oil on top of that]. One caveat though: I've only been to DiFara's a few times (and not in over a year) so my memory of that experience may be less than crisp. Also they no longer mention DiFaras on their signs, though the front-door to the restaurant has one of those "Zagat Rated" stickers.
That said I still think it is a pretty good slice: too cheesy and not enough sauce but pretty good for the nabe. I think it is better than Joe's becuase it has a tastier crust, more substantial. One nice touch is that they have grated, not powdered parm. I'll try their square slice (and maybe the eggplant parm hero $7 or $8) next time.