To my knowledge there are two companies (re)making the sterling. Wise Lite Arms makes the one with the skinny barrel sticking out of the front. Masterpiece Arms make the "type 2" that has the ventilated barrel shroud completely covering the 16" barrel.
I have never seen the type 2 myself, but the reports I've seen are good.
I have a couple WLA sterlings. Each is unique. When you are rebuilding from cut up kits, there will always be some differences. The first one I bought was nicely put together. I happy enough with it to buy a second. The second was pretty poor. The sights were off, the vent holes didn't line up well with the sights, the folding stock was off center, and the rear weld was pretty poor and not completely finished. Oh, and stock hinge was rather rusty and missing a washer on one side. I sent that back to WLA and they replaced it with another for free!!! The replacement gun is very nice and straight.
If there is a common problem with them, it is that they shoot low. Both of mine shot 12-16" low at 25 yards. I had to file the sight down in order to get the POA to the POI. Also, IIRC, they had some issues with the firing pins breaking with the first guns. I think the fixed this issue, however.
Yes, sten mags will work in the sterling. But, sterling mags won't work in a sten.