My DS has asthma (usually only triggered when traveling, thus our
Disney cruise was not a fun time with him developing a severe case of Bronchitis triggered by it). He almost always needs a nebulizer when we go away, so I had requested this for our trip to the BWI a few years ago.
Yes, it's true, that when you check in, they are working on your room, so NO upgrades or room changes (and I was disappointed actually, since they were going to offer us to upgrade for a fee to concierge level).
They steam clean the carpet, change the A/C filters, change out any soft goods like quilts (back in the day).
It turned out to be the best thing ever. That trip, he only needed to use his nebulizer one time. He breathed so much better than most trips!
PS: He is now a high school senior, and we traveled over Thanksgiving to visit family (usually don't), and he spent the whole week after Thanksgiving out with an asthma attack. It was awful.
If you have any breathing issues, I would recommend it! It helped so much! My DS is older now, and it's more rare for him to have issues, but for sensitive ones it's worth it!