It is what you expect it to be. Lone Star is long on that contrived southwestern bar room charm and short on really worthwhile food. I had the "Big Rig" burrito, one of the entrees the place is known for. It was a perfectly serviceable burrito, but not worth the $15 I paid for it.
The staff were very pleasant and attentive without hovering, though clearly there is a dynamic going on that you and I, as customers not employees, aren't supposed to see (but do) or understand (and can't).
The Bottom Line:
If you want a standard tex-mex meal with standard beer because you're a tourist staying nearby Lone Star makes sense and will fill your appetite. If you're interested in something more, you'll need to find somewhere else to go.