I wouldn't worry too much about the * marked tyres unless your running X Drive, it'll only restrict your choice of tyres, what tends to happen is BMW will approve certain tyres for a model and then those tyre models will become non-competitive as tyre technology moves on leaving you with only the choice of older tyre types.
Makes very little difference in my experience on the xdrive this is my second xd running non * marked tyres. 1st one ran on goodyear egales F1 (335xd) and the current car (330xd) running on Mich MPS 4 all round. Never had any issues.
I don't run * marked on our X3 and haven't had issues however, if I was under a BMW warranty I would fit them to avoid any potential rejected warranty claims....the * marked tyres have been approved for use with each vehicle and can't be used as an excuse to void and X Drive claims.
