I'm finishing my first year as Gold Elite, and have usually enjoyed the benefits including upgrades. I don't go into a stay expecting an upgrade, and have often been pleasantly surprised. (The grand prize was a six room presidential suite at the Gaylord National Harbor, from a discounted standard convention room !)
But at many hotels I am told that there is no upgrade "available". While I know that can be true at a really busy hotel, sometimes I'm looking around at a deserted property.
Last weekend I stayed at the Residence Inn Times Square, and the hotel certainly was reasonably busy, but again I was told no upgrade available. I had the basic studio room, so even a 1 bedroom or an Empire State Building view Corner would be an upgrade. I was skeptical, and checked online for the same nights and discovered that all higher level rooms were still available on the website, and for exactly the same price they were at when I had booked several weeks earlier. My understanding of the Marriott room rate system tells me that they weren't close to full occupancy (as several other Marriott's nearby had their rates triple over the same timeframe). Frankly I think the clerk just wanted me to move on as we got there past regular hours, and there was no one there to argue with.
Bottom line- Is there a way to enforce the upgrade policy?
I think it's sort of like karma. Sometimes it happens; sometimes it doesn't; usually it happens when you most need it.
Here's how I roll: I only ask if I need it. Two people traveling, don't need it. Traveling with the family, I'll ask.
I'm happy to report that tomorrow I'm checking in to a place that I asked for the upgrade when I stayed there last Friday.
I hope I can get the guy at the front desk's name. He said he'd take care of me, he was right!
It's difficult to enforce something that's not guaranteed. Some upgrades are not part of the benefits list. For example. certain types of lounge access (Like Griffin Club or RC Club). Suites are not guaranteed.
However, I usually try to get all info I can when asking for an upgrade. I travel weekly for work and never need upgrades for that travel. All upgrades I request are for leisure travel for me and the Mrs. So, I really want them at those times. Like you, I check availability before I get there. If I am turned down, I tell them certain inventory was available for sale and to explain why I cannot get that room. In many cases, that takes care of it. I am always polite and never take a position of entitlement. That never works. I have seen people fail using that often.
Other factors such as length of stay will impact success. A 10-14 night stay will decrease upgrades. So, I try to keep perspective and really tell them what I am looking for. That way they can check exactly on that. Usually works.
I do so HATE being jerked around on any benefit. Just give it to me straight. I have chosen Marriott nearly exclusively. My loyalty is worth something. I cannot get an upgrade every time, but help me when you can. I have reasonable expectations.
Cash and points upgrades basically share the same terms and conditions, so my comment is mostly on points upgrades:
It is whimsical at best for getting upgrades, especially anything more than a "single level" of room upgrade. Every time I have used points for vacationing, I, like you, went online "anonymously" as a "cash" patron using the same dates as what I had booked and EVERY TIME there were better rooms available for cash than to what I was upgraded.
Oh boy, there I go again . . . . .