I also have recently (In the last year) replaced the refer in my MH.
It does not cool as well as the unit I had in my last trailer, but with the addition on the 12 VDC Muffin fan, blowing straight up the flue, it will get very cold (35 deg F) when set on the lowest temp setting. The freezer keeps stuff rock hard.
I installed the fan with an on/off switch, and it came with a temp. seneor that I have attached to the exterior flue of the refer. As the temp increases the speed increases. I am still working on the optimal placement of the temp sensor.
One other thing that makes a diffrence is wether you have an awning over your refer space. The refer will cool much better if the exterior skin is shaded.
WBCCI #5501 AIR # 49
1978 Argosy 28 foot Motorhome
Wise men talk because they have something to say; fools, because they have to say something. -- Plato