I can relate a 'lil to what OP is referring to in that there are some downsides of "upgrades". Most of my travels are domestic and although I appreciate the upgrade to FC when I get it, I do not value (flight upgrades) as much as most who post here.

For cars I have often been Comp "upgraded" to a full size Crown Vic or mini or full size Vans when just traveling by myself. Sucks to park them in many hotel parking lots that I frequent (I turn them down if I have the choice, but sometimes that is all they have left).

For flights, If I know ahead of time that I am upgraded, I appreciate it much more then a last minute upgrade at the gate (after I already bought lunch). If the later and given a bulkhead seat it can be a minor problem storing a laptop since first has already boarded, then I find out when I board (not knowing I was upgraded) and find the overhead bins towards the front of the plane are already full - plus I just prefer the legroom in coach exit row seats vice most first bulkhead seats.

For hotels, upgrades are always better unless the "upgrade" is for a handicapped room and one is not handicapped. For those of us who stay at HH properties I have yet to see any advantage (or disadvantaged) of being "upgraded" to the Executive Floor (with exception to my stay in Curacao where I had the most excellent view).