Seems to maintain a constant temperature, I haven't had any issue so far.
This is a manual defrost freezer .. no frost build up yet, I keep extras in it so not opening it everyday which I assume helps keep frost at a minimum.
This is small, top shelf is full depth & not much height, but bottom isn't, fits about 6 bags of frozen veggies standing up.
I didn't have room for a larger freezer, but this works for those extras