My husband and I decided to order from Sliceria last night after reading a mention of it on Serious Eats. THe website was malfunctioning a little bit (I think) since I was told on the phone that delivery to my street (42nd) was fine but on the site, it said "can't deliver to that address". This was a minor inconvenience since I'd wanted to pay with plastic, which the guy on the phone said was only possible online. No matter, I ordered over the phone; half-sausage large pie!
It arrived pretty promptly and hot and the delivery kid was nice - plus, I don't think they charged us for the half-sausage since our pie was $10!
I was pretty impressed with my first bite - nice balance between sauce and cheese, a little browned but not at all dry, crust was a good balance of crusty and a little chewy. My one complaint on taste - and my husband agreed - was that the sauce was really rather sweet! It was sort of odd to notice it after one slice, but there was definitely a sweetness that detracted from the pie.
Another thing: although the reviews said neapolitan it really was a lot more like NY street slice than anything else. However, you could definitely tell they were more superior ingredients - the cheese actually tasted like cheese - than some of the crappy pizza places that unfortunately you find in Sunset Park.
Altogether I'd say it was a solid 7 out of 10 for decent, polite delivery, good prices, and decent ingredients. Plus, I'm pleased to see new businesses open in Sunset Park with enthusiasm. Not sure I'll switch from Johnny's but I'll definitely try it again in a few months to see if they've improved their formula as they go!