One thing I haven't seen anyone mention is space. Full time in a van is like living in a cave as soon as the weather turns. Too much fridge just means less living and storage space. As said most people who aren't going on a full-blown expedition can pretty much graze from store to store for food. Make sure you pull out a tape measure and find something that is going to tuck away where you want it.
Have an idea of what is really going to go in there. If it is going to be mostly beer then a top door is great. Cans and bottles stack nicely, and you can sit on top or use it as a work surface. If you're going to have mostly smaller food items, veggies, etc then it turns into a major hassle. Everything has to come out to get something on the bottom, and fragile stuff like fruit gets smashed.
Displays are nice, but do you really need them? If I could change something I would get a model that only lights up when prompted with maybe just one small indicator led to tell me it is running. An OLED screen that's on 24/7 telling me the inside temp is a waste of power, lights up the van at night when you are trying to sleep, and draws unwanted attention to you when people walk by and see a glow.
Finally make sure the warranty is BOMBER. You are going to be pushing the fridge to the limits with extended constant use. I killed a Dometic in 3 months of alternating dust, damp, high temps, constant vibration and bumps. That could have been a crisis, but they have a 2 year warranty that is renewed if they give you a replacement. Most camper retailers are service centers so I can just drop it off and have them deal with it.
I think I am running a 54 liter. It was the biggest that I could put into the space where I wanted my fridge - right behind the driver. Here's a look
https://www.expeditionportal.com/forum/threads/q-flights-rb-e250-quigley-build.163811/page-7