J. B.
Yelp
First off, the view from this place is unparalleled. The overall ambiance, and service is also exceptional. The tasting courses are plated immediately after the sommelier pours the wine pairing, and explains the wine and how it'll fit in with the dish. The timing of this seems difficult, as he is covering every table in the restaurant, but you wouldn't know it based on how seamless the service is.
Overall, the food was quite good, but I'm not sure that it was life-changing in anyway, which is typically the standard I hold restaurants with Michelin stars. One of the highlights was the tomato ice cream that accompanied a crayfish salad; this was an innovative way to bring acidity to the dish. In the same light, the apple palate cleanser brought that pop of acid and was quite original, not to mention the gorgeous presentation. The meat course of perfectly prepared duck was excellent, and paired with a hazelnut praline, adding texture to the dish.
All-in-all Mirador was a 4.5 star experience. It was excellent, sure, but I've had better tasting menus in other places. So if you consider that fact, coupled with San Seb having the best food in the world; it needs to be knocked down a star.
Tip - this place is off the beaten path, so you'll need to take a cab up. The staff will kindly call you one for your return.