I'll agree that because of where it's located (the building complex), it can be hard to find if one doesn't know what to look for, but my stays there have been outstanding in terms of service.
Once I had an early flight out of MUC and mentioned that I'd have to depart before the breakfast room opened (the rate included breakfast). They volunteered to have room service bring me a hot breakfast at no extra charge and had it delivered at 0400!
(I was Gold at the time, but I don't think that influenced the decision.)