I was thinking of that, but I'm a fan of ease... I just ordered them and figure that if they suck, I'll take em to target and get my money back. A few reviews I've read have people saying they are, indeed, airtight.
As for the temp issue... I bet they do have fairly thin walls, that's why I was saying I was gonna bury them in a closet somewhere... in a cool room
I have a place in mind where temps shouldn't fluctuate too much.
I plan on keeping my one cooler for my super special boxes, though, and use these here for regular production stuff.