I just bought the Sam's Club MES 40 today. I returned an unused 20070508 model received as a Christmas gift to Gander Mountain today as well. The 20070508 model was not the upgraded 40 with the new 1,200 watt element, "service" panel in back, and smaller chip tray.
The model number of the Sam's Club MES 40 I bought today is 20070810. I've seen it reported elsewhere as 20070710, but mine is the 20070810 version, and it IS
the new version with 1,200 watt element, "service" panel on back, and smaller chip tray - of course black box, silver front door with window, etc., etc. too.
I haven't unboxed mine yet, although I went over the "display" model in detail - engineers tend to do that
. Here is a photo of the model number on the box.
As soon as it "warms" up here in Southeast Texas, I'll "season" my new MES 40, and do some brisket and ribs.