I have had very good after sales experience with MS and my Surface Pro, but I do have one of their stores near my home and the service was dealt with at the local level by the store manager. I have never had any dealing with MS beyond the local store.
I just purchased a Lenovo, but have not yet had any reason to contact them beyond some initial pre-sales questions.
Laptop Magazine still ranked Lenovo overall as far as brand, but their customer service supposedly slipped a little and they gave it an even score to MS, with Apple and Dell leading that category.
Of course, take Laptop Magazines rankings for what it is, an opinion