At about three months into a trip I feel a strong need for more space inside the Dormobile and start lusting after one or those really large off road RVs. And that is just with one person and a dog in the Dormie. I agree with Ian in that a Dormobile or Carawagon is really sized for one person to travel comfortably and it you have two or more you really need to have a hybrid camping style with your cooking and sleeping inside and the rest of your camp outside the vehicle.
In answer to the question of what makes life comfy to me it means 3 things: a good night's sleep, good food and a portapotie (Us women do not like exposing our lower half to the outside world).
For a Dormie a good night's sleep involves a good sleeping bag and an insulating mat if sleeping up top or an air mattress of some kind when sleeping below.
For cooking nothing beats a good compressor type refrigerator to allow you to eat fresh food. Anodized thick wall pots have excellent conductivity and allows you to cook foods more evenly using less propane than other types of cookware and of course I use the broiler all the time. I like fancy thick plastic dishes for eating. They look like china, don't break and have a low heat conductivity so they do not draw the heat out of your food before you can finish your meal. I also use a cloth place setting and matching cloth napkins for that feeling of a bit of luxury on the trail.
I don't know if they have them in Europe but in the US wineries often have small wood presentation cases that are made for one, two or three bottles of wine. I have one that holds three bottles. It fits inside the area of the folded up Dormie wardrobe jump seat, alongside a box of cereal.
On the wall next to the sink I have a knife holder for my sharp knives and a little basket shelf to keep dish washing supplies then I'm camped.

The gray kit next to my knives is my signal kit for attracting rescue. If I'm in need of help I don't want to be shy in attracting attention. I can pop orange smoke in the daylight and have very bright signal flairs for night.
The mirror on the inside of the wardrobe cabinet door can become a grooming station with the addition of some holders to keep grooming items. I have two wooden holders below the mirror in my door to keep grooming toiletries together in an easy to access location. The second holder is directly below the one in the picture.
There is a lot of wasted space under a Dormobile cooker. That can be vastly improved by aking a page out of the Carawagon play book. I once looked inside of a two door command Carawagon and noticed modifications for increased storage in the left rear corner. The top and side of the side bench behind the rear wheel arch was removed and the floor under the side bench area was cut away then an aluminum drop box was added to lower the floor in that area down to the bottom of chassis level. That significantly adds to the under cooker storage area and makes it more versatile for storing cooking gear. On the opposite side of the vehicle I have mounted my second battery and an emergency shut off switch under the side bench area.
There is empty space across the back above the the rear door. I have added a short cabinet across the back above the rear door. This is the perfect size to store small boxes of tea. I can easily carry seven tea boxes for different varieties of tea. And of course adding a door to the Dormobile spice cabinet makes it a lot more useful.
Painting the inside top of the Dormobile fiberglass roof makes the interior feel cleaner and more cheery.
Anyway, these are just a few of the things I have done to make life a little more comfy on long trips.
One thing that I noticed right way with LR Dormobiles is that people who spend a lot of time traveling in them become focused more on having the interior best fit their needs and people who do not travel on long trips tend to be focused on concourse like originality.