I have this StayorGo Hamilton Beach slow cooker. It's large enough to hold 2lbs of beans and plenty of water. I like the clips on the side that make it easier to take to a pot luck.
I haven't used it to cook a pot roast in a very long time. Really, aside from cooking my beans, I don't use it for much else. I do want a small one to make yogurt in. Maybe I'll make that a goal for the New Year.