Dan,
The 721001 came out in Fall 2008 and was the first significant update to the WSM in about 25 years. It has these features that the 2820 does not have: <UL TYPE=SQUARE> <LI>A built-in thermometer with range of 100-350*F
<LI>Improved access door design: Knob now indicates closed position; improved spring-loaded latch; door can hang open from the side of the cooker or can be removed entirely
<LI>Increased water pan capacity to 2 gallons.
<LI>Sturdier legs
<LI>Heat shield below charcoal bowl protects surface below the cooker
<LI>Improved owners manual
<LI>Improved packaging provides better protection during shipping [/list]If buying the WSM online, please consider purchasing from Amazon using the links on the homepage. It's through the generous support of members shopping at Amazon that I am able to bring you TVWB free of charge.
As was discussed in a recent thread, you will occasionally find the WSM 721001 on Amazon for $244.99 with free shipping on "Friday Sale".
Regards,
Chris