I have had my 63Q cooler now for about 2 weeks and have done some intensive testing to see how well it works and I am quite happy so far. At first I was a little freaked out, when after 5 days I noticed the temp 35 deg F, but the inside cooler temp was like 45 deg F....( it was using only 130 watts per day however ) so I contacted Sierra Expeditions and they put me in contact with the factory rep who was willing to take the unit back. After some more home testing I discovered the temp inside the box was different at different locations. Colder on the outside walls, bottom & warmer in the middle and on the top. I now found my personal sweet spot at the 20 deg setting, at that temperature my soda's is ICE - COLD at 30 deg, the new stuff I put in on top does not freeze. If I put in something frozen on the bottom, it stays 100% frozen. YAHOO , I now have the best of both worlds, Freezer & cooler in one unit. At this setting it is using about 350 watts per day in 75 deg temp. Looks like (1) - 80 watt solar panel might do the trick.
I compared this unit to the 40-Q Engel cooler, it has 50% more space for the same $$, it also has the German Danfos 35 compressor - which is #1 in the world over & it also has 3 years warranty vs 2 years from Engel, so I am getting triple the BANK - for my BUCK !! - Its a no brainer in my opinion.