I've owned 2 AL48's in the past, one 12ga and one 20ga. I had them for about 2 years, shot them alot, then sold them as a pair. They are basically an aluminum receiver A-5 (Browning) with the same recoil action. The lighter receiver made the 12ga a real "kicker" with anything but "low base" shells, but the 20ga was a great bird gun; however, it was easy to "overswing" on "pass shots" because of its "ultra" light weight.
I never had a malfunction with either gauge, even with reloads. I would buy another in a 20ga at a reasonable price, but I'd pay extra for one in a "28".
I think you'll like your purchase.