This past July I replaced my 120V Grunert holding plate system with a 12
V system that I built from parts from RParts.com. My major reasons for
doing this were (not necessarily in any order):

1) I could generate 12V from a large number of sources:

a) Solar panels
b) A KISS wind generator
c) The Heart Inverter/Charger that runs off the generator or shore AC
d) The alternator

2) My Fischer Panda generator was completely unreliable. As a result I
was trying to move away from relying on 120V. The Fischer Panda was
replaced by a NextGen generator which I hope will be much more reliable.

3) I am virtually never at a dock. I spend 6-8 months a year cruising
and am headed to the South Pacific this year. When I am at dock I can
use the shore power through the charger.

4) My holding plates do a great job of of maintaining temperature in the
compartments. I personally know of very few cruisers who use evaporator
style systems, other than those who have very small systems. Then
again, I know some cruisers who don't have *any* refrigeration, but I
can't imagine living that way!

5) After researching my various options I decided upon a 1/2 HP Glacier
Bay motor direct coupled to a Bitzer IIY compressor. For all intents
and purposes, this is a Glacier Bay system except that I use Grunert
holding plates rather than Glacier Bay holding plates. The Glacier Bay
holding plates are more efficient due to their use of spider capilary
tubes, but I couldn't justify the cost relative to the performance gain.
I switched from R404A to R134A.

6) I wanted to build the entire system myself as I need to maintain the
system while out cruising. Before doing this refrigeration was a bit of
a mystery. Now I've got a good handle on it as well as having the tools
(pumps, sniffers, etc) necessary to maintain it.

7) The system is running just great. It runs for about 2 to 2.5 hours
per day in daily day time temps in the low 90s and night time temps in
to low 80s. It cycles on demand. I redid the circuitry so that only
one zone runs at a time. This is MUCH more efficient than allowing both
zones to run simultaneously.

I don't know if this helps at all, but it's just one more data point.

-- Geoff