Whilst not 'exactly' the same this one has been on 24/7 for about 2 years with no apparent issues (it's not normally in that position!).
Only used for DMR and DAPNET so not 'heavy' usage.
There is another the same polycarbonate case design in the cubby box of my car and that's been fine too
I also have one of the really cheap Chinese pressed steel cases and that does stay cooler (just doesn't look so funky)
Mine arrived today, went together easily and looks a great deal better than the black metal case that came with the hot spot. I bought 2, one clear and one lazer lime, from C4Labs. Thanks for the responses.