The airport shuttle sold it for me.
Like many reviewers before me, I chose the Holiday Inn IAH for its close proximity to the airport, and especially for the free shuttle. The latter was definitely the selling point for me. I called them up when I got through customs and was picked up ten minutes later. Similarly, the shuttle left at 4:30am to get me back in plenty of time for my 6am flight. Inbetween, I had an OK hotel experience, but nothing to write home about. The reception staff were great, and very helpful. The room was large and well appointed, but the bathroom was small, and the toilet blocked more than once (no, not because of anything I did; the water flow is low and the aperture is too small!). I ate in the adjacent restaurant, and was not blown away by the food quality (although the quantity, as you would expect, was excessive). My chicken fried steak looked very large, but on closer inspection I found out that the batter was what was making it look big! In summary, this hotel is OK for a late night arrival or early morning departure from the airport, and the price is good, but this place is a little jaded and needs a facelift.