It pretty much the same as the old 390's with a few differences. It has the automatic magazine cutoff but does not have the bolt lock lever on the left side of the receiver. They only come in B/S with a 28" barrel in the 12 gauge and 26" in 20 gauge.
The AL 391 is a whole different gun. It has a totaly different gas system and a super slim forearm. All most all of the 390's have an angled receiver where the AL 391's only have the rounded receiver.
The Wal Mart 390 is a good value even at the $529.00 price at my local stores.