I have the Pungo and you'll certainly not need anything more stable than that. In fact, if anything I'll want my next kayak to be more of a true sea kayak than the recreational class that the Pungo represents.
Haven't seen the Old Town. Maybe you can get a test spin in both models.
As for anchoring...the Pungo has loops at each end with little carrying gizmos on them. An anchor line passed through the bow loop or affixed directly to it will keep you positioned bow-into-current. But then, how do you retrieve the bowline? Best I've come up with is another rope attached to the anchor line ahead of the loop, so that you can pull the anchor line into the cockpit.