I am generally happy with my Sea Frost, I have both an older ED I didn't install, and a separate newer 12V system I did install. You are correct ... my ED "install" has issues (I didn't do it !), probably not Cleve's issues. My first problem was a rubber hose to copper fitting leak. I looked for days to find the leak, did everything I was suppose to do. One tech showed up and he couldn't find it. Then another came and he didn't find it, brought out the electronic leak detector and we still couldn't find it. Took us hours, we checked & jiggled every connection, went over every line. We just happened to move this one connection at the rubber hose just the right way one time, and then we found the leak. But it only leaked when it was moved a certain way, in a certain position, we weren't even sure it was it for awhile. We were lucky to have found it. I thought afterwards this was kind of silly, had we not been lucky, we never would have found it. I would think the connections might have a better design. And the second issue was a failed compressor. During a 3 month trip, it was working great, and then one day it wasn't. I still haven't figured out why it quit, I replaced all the lines a couple years ago, if there is another leak, I am curious why the Sea Frost does not have some kind of detection device or switch that will shut down the system prior to catastrophic failure, if in fact refrigerant leaks are something to be reckoned with.
Since I need to at least replace the Compressor and the RFD, and because my Holding Plate install has issues and I think could / should be a bit larger, now would be the time to research other manufacturers to see if there are others out there that may be better. I'm also a little puzzled and curious why the Sea Frost relies much on touch & sight tests for system functioning, I would think something a bit more precise and easily monitored / watched might be a good thing.
Like you, I am very happy with the Sea Frost 12V system, so far working like a charm. If you are getting 30Ah, you are doing extraordinarily well. If I do not run our ED system, I will be twice that, but we are in the Tropics, in the spring / early summer, where the water is mid to high 80's and air temps low 90's. I assume you don't have a freezer and assume your box is smaller, we do have a freezer and our box 7 CF. I have been in the process of replacing insulation, lids, and seals & gaskets, and am generally happy with the box, although I have a bit more digging to do when I replace my countertops, I can't believe how many voids I found in and around the Box. Sabre obviously did well with your Box, you likely have state-of-the-art insulating materials and plenty of thickness, not very common for a production builder to pay that much attention and detail to the Box construction.
Thanks, cheers, john