On 2011-11-22, NT wrote:

Frost frees are inherently unreliable. If you want something to last 5
yrs you may be ok, but if you expect a fridge freezer to be likely to
last 20 years, avoid frost frees. I'd rather defrost a few times when
I choose than have a freezer die unplanned.

With non frost frees, reliability is generally good across brands. The
value types you can get for £99 have short design life, but how long
they last IRL I dont know.

http://wiki.diyfaq.org.uk/index.php?title=Fridge

Thanks (to you & the others who replied) for the advice. The problem
is that all the fridge-freezers near the capacity of our current one
seem to be frost-free, but we've found a non-frost-free Siemens model
that's close.