It gets "pill-y". Difficult to explain. Mine were Audi 'silver grey' which were very light, so even mild dirt really stood out.

 

You can use a sweater trimmer (looks like an electric razor) and it will trim off all the balled up alcantara. I personally like the alcantara because it won't get hot in the sun if left out in the sun for an hour, and it also holds you in your seat a little better than an all leather. With regards to the R8, I'd get the full leather package to have the dash, door handles, etc. in leather.