Obviously not gospel, but this guy seems to have done his research.
http://home.iprimus.com.au/rfh/portablefridges.html
Looks like he has done some research, and has quite a bit of experience. Only thing I saw was his statement that the Engle was loud... I have not found my Engle to be loud, but mine is about half the size of the models he is testing.
I haven't found my Engel to be a problem in terms of noise. It does cause some vibration, but as long as I stow the stove broiler tray and such properly, it isn't a problem.