I have an opportunity to pick up one or the other for the same price. Both appear to be in very good condition.
Any opions or experiences out there that might help me with which one to go with?

Having both guns, I would say that I treasure my Marlins quite a bit more. If you are looking for a slimmer carry gun, many prefer the Winchester. I don't like mine as much because of the rebounding trigger and loose action. The Marlin feels more sturdy, and in my hands is more accurate (mostly because of the trigger). I would say that in 30-30, the cast may well be easier to shoot in a Winnie.

In my hands, the Marlin's action is more sure and foolproof. One can clean the gun from the breach more easily as well.

I have a Ted Williams Model 100. It is a top eject and it does not have the rebounding hammer. It is very accurate with cast bullets. I have never shot jacketed bullets in it but if it shoots cast well it should shoot jacketed very well. I am very satisfied with the rifle.

I have no experience with the 30AS. I have a 1952 vintage 336A that is rough as a cob inside and doesn't shoot very good. I am disappointed in that rifle but I am going to tinker with it and see if I can improve it.

Moral? You never know what you will get til you shoot it.