I think it depends a lot on the specific property and how often you stay there. At my current regular property, which I am at 3 to 4 times a month, I get unsolicited suite upgrades near %100 of the time and I am almost always using mobile check in. Properties that are good about upgrades probably don't differentiate between standard and mobile check-in. Time of day of the check in probably has much more impact. YMMV...

--Jon