I recently purchased this Rival 6.5 qt. programmable crock-pot
. The timer is programmable in half-hour increments, up to 20 hours. When the cooking period finishes, it automatically goes to warm for up to 6 hours. Unlike some newer models, the low setting doesn't seem to be set too high. First thing I did was fill it part way with water and cooked on low for eight hours. After that time the water temperature read about 192*F.
The unit has a few minuses: The outside gets really hot, even when set to low. It has two silicon coated handles, but I still had to use oven mitts when moving it. The outer surface opposite the controls is hotter still. Also, the lid doesn't fit real tight. This isn't an issue for me because I use a liner bag when slow cooking and that makes the cover fit better. Some of the reviews on Amazon indicate that the lid wasn't even close to fitting properly, but that wasn't the case for my unit. I think the lid would be fine even without using a liner bag. Also, the current price on Amazon ($119.99) is $20 higher than when I purchased it two weeks ago.
I bought this unit because it's oval and because it was recommended by America's Test Kitchen in their recent book, Slow Cooker Revolution
. In fact, all the recipes in that book were tested with the above crock-pot. I'd recommend buying the book if you decide to buy the crock-pot.