I tried mobile check-in at a SHS where I'm a regular. I used the app around noon on the day of check-in. About 10 minutes later I got a message that the room was ready. When I arrived at the hotel around 6:00 pm I was given a ground floor room. My MR profile requests a high floor room and I have always received one at this property. It wasn't a big deal at all, but it is an indication that app check-in is not working as it should. NB the property was lightly booked during my stay.