They are beautiful dogs. I have a personal reason for wanting one but it doesn’t seem likely that would happen. I heard one description of them as having all the desirable qualities of a German Shepherd and none of the undesirable ones (neuroses was mentioned but the wiki indicates that as a potential problem).
Much is made of the need for activity in a lot of dogs, and that should be considered strongly, but many large dogs do not need more than fair size yard and weekly adventures. For any dog a strong relationship with it’s best friend and family is going to do far more for quality of life than constant play and exercise. I don’t mean at all to downplay the need for activity in a dog’s life, but large and active dogs can manage quite well in a more sedate lifestyle when their other needs are taken care of. Working dogs have a strong work ethic, even if their job is just watching the home you can make them feel useful. Any dog can be involved in all of your day to day household activities even if their only job is to supervise 
With an adult dog it may not be a good idea to change it’s activity level too much, but younger dogs can be adjust over time to a lot of circumstances, although not much can be done about the activity level of puppies.
Back to the Malinois, the part that I like is that’s always described as an intelligent dog. Okay, intelligent dogs can be challenging on occasion, but in my experience you it is the intelligent dog that will best adapt and be comfortable in his environment. Intelligent dogs love to be praised for their intelligence, give them something to learn and they’ll be just as satisfied as they would be from a game of Dog Frisbee*.
*Official rules of Dog Frisbee
- Human throws the Frisbee
- Dog gets Frisbee then runs around with human chasing him. Dog must avoid letting go of Frisbee because stupid human will just throw it away again if he gets it back.
- Human finally recovers Frisbee and says “Alright, that’s enough”.
- Dog looks adorably disappointed that the game is over
- Stupid human says “Alright, but you better bring it back this time”.
- Goto step 1