I just got a Mak 90 and it's by far best AK I've ever owned. So smooth.
I had a MAK and while it did have a smooth action(compared to the Bulgarian Century AK-74 and the WASR 10/63 that I had) I just wasn't all that impressed by it. I have fondled a few Arsenals and they really are all that they are cracked up to be. I'm trying to trade my AR for one right now.