Way back in the day (i.e. 90's and early 00's) I used to use the TVL rate quite a bit. (I did a lot of work for airlines.) Back then the TVL rate almost always was significantly cheaper than other rates. For example, I used to travel down to the Ft. Lauderdale area for Continental (they had an IT group down in Miramar back then.) The Harbor Beach Marriott would usually have a TVL rate that they would let me use for well over half off their normal rates (i.e. I could stay on the beach there for about the same as I could at a CY in Plantation, FL). ^

But about 15 or so years ago, I started noticing the TVL rates at a lot of hotels seemed to start creeping up. IOW, they weren't all that cheap anymore. In fact, my company's corporate rates were cheaper in a number of instances. The result is I haven't used the TVL rate in over a decade now (note that I also changed jobs and clients so I wasn't supporting the airline industry any longer too.)

But I will agree with most here in that even back then, those deeply discounted rates (TVL, GOV, etc.) would almost always require me to provide some type of documentation to show I was eligible (compared to using corporate rates where I can't remember the last time I was carded.)