My brother bought one quite a while back and I've shot it a few times at the range. It's reliable, but I don't love it especially as a sporting arm. Oleg Volk did a photoshoot with one a while back. I can understand the folding stock and pistol grip. The 20 round drum must weight a ton, but ok. The dark earth refinish kind of looks nice, I guess.
Honestly I can take or leave all of these improvements. What is a must for a Saigo? Better sights. The stock sight radius is pitiful and the sights are really small. Even the bead on the end of my 590 puts them to shame. Oleg's gun doesn't seem to have these.