Hi, welcome to the forum.
From what i've heard on the forum, some people dont like the way they drive. I suppose it depends on what you are used to and the intended use for the vehicle.
We had one in the family and it wasn't bad at most things. It was quiet, comfortable on the inside if not the best quality interior. It was ok to drive on the road and surprisingly good off road. A compromise but its a capable 4x4 so what you expect.
Reliabilty wise, it needed the injectors resealing with new copper washers (not a big job but fairly common)
It had two injectors replaced (had to have them programed at a garage)
The water pump needed replacing (easy to change)
Other things to watch are the rear springs and general knocks from suspension bushes as they are big heavy cars with lots of joints.
Our Ml had covered circa 240k miles when sold. Cant really complain but the cosmetic rust made it look very tatty.