My experience with the 3 way fridge has been good overall.
Previously we had a T@B Clamshell with the 2 way (12vDC/120vAC) compressor fridge and it was pretty terrible. The compressor was noisy as hell and it was right by where our heads were when we slept. It would suck the battery down in just a few hours of use, so for that reason we ONLY used the fridge during the day and ONLY when we were hooked up to 120vAC power. For all practical purposes it was useless to us and we only kept non-spoilable food and drinks in it. Anything that could spoil went into the Truckfridge in the Suburban.
After 3 years in the T@B, we decided we wanted a bigger camper, and one with a bathroom inside (getting older!)
We went with an R-Pod 179, which we purchased in January of 2018. We didn't buy it new, we bought it from the original purchasers and they barely used it (I think they used it 3x last year after buying it new) so for all practical purposes it was a "new" trailer to us, it just didn't come with a warranty.
One of the features I was most interested in on the R-Pod was the 3 way Dometic fridge.
We have used ours in all 3 modes. Since we store the trailer at home, in our side yard, we keep it plugged into a 120v AC power source and the fridge stays on 120v. When we travel we put it into 12v battery mode, and when we are camping without shore power we run it on propane. It seems to run very well on propane, certainly cold enough to keep our food cold and there is even a freezer compartement up top and yes, it stays cold enough to freeze ice cubes. About the only thing we have to do is when switching from 12vDC to propane, we first have to light the stove (which is downstream from the fridge) and let the stove burn for a few minutes to bleed out any air from the propane lines. Once we've done that, it's as simple as pushing the button for "gas" and the fridge will run fine. It uses very little propane in that mode to keep the fridge cold.
I'm on a couple of Facebook groups for R-pod owners (there's a huge R-pod community which makes it very easy to resolve problems because I can tap into the "hive mind" whenever I have a problem - that's literally the main reason we went with a "real" R-pod instead of one of the many R-pod "clones" out there) and others seem to have had issues with their 3 way fridges not cooling, or not cooling very well. I don't know if the issue is maintenance or just the luck of the draw but (knock wood!) ours has worked fine for 12 camping trips so far (8 with shore power and 4 without) and it's worked fine every time.
EDITED TO ADD: I should point out that we also are currently running 2 x 12v deep cycle batteries hooked up in series, and I also have a 100w solar panel that plugs into the side of the trailer. When we camp without shore power I always use the solar panel to keep the batteries topped off. I have a set of 6v golf cart batteries, too, and if I get motivated this winter I might install them in place of the 12v (the 2 x 12v batteries were on the camper when we bought it, as were the dual propane tanks.) Our Pod is the "Hood River Edition" that has the higher suspension and "off road" tires, which makes it a little nicer for dirt-road camping (we'd never take it on a "serious" off road trail but Forest Service roads are fine.)
As I said, it keeps food ice cold, literally. And only have the temp setting on 3 out of a possible 5 bars. I actually had to turn it down because on one trip I had it set to 4 bars and a soda can froze and exploded in the fridge.
