Like The Big Troll says, ATX cases have seven slots, mATX cases have four. Personally, I have been satisfied with all of the Rosewill cases I've bought, although the last one did have a too-loud fan I replaced.
Incidentally, TBT, that name always reminds me of the cave troll in GW2 in Queensdale that somebody sets off on a rampage every now and then. Funny...