Most are very nice. Towels, soap, blow dryers...
You pay and get assigned a # for the shower room. Then you have a code on your receipt. The code allows you to enter the shower.
Maids are there to clean the rooms between each use. Many are larger than any hotel bathroom.
They also have TV viewing areas. Some are quite comfortable with couches and other have hard plastic chairs like the DMV have.
If a movie was playing TC might sit for awhile and leave before the movie ends.
I'm not sure how often a news channel would be on.
ET could move pretty quickly in and out and barely be seen.
They however, have NUMEROUS cameras, so they would be on surveillance footage.
More photos at link:
http://texasvanagons.com/truck-stop-showers/