I don't know about discs, but I had a Memorex CDRW unit that was the worst piece of crap ever designed by man.
It burned discs all right, but it had trouble reading discs; the disc would spin up, CDRW would have read a couple of bytes off it, then spin down. Repeat ad nauseum. It often took a whole hour just to read a 650MB disc with this thing.
Stay clear off Memorex.