It definitely misses the mark on being "Authentic Texas BBQ".
I had just returned from Texas for the umpteenth time when I tried Hayden Block so it was the perfect time for a fair comparison and unfortunately it just doesn't compare to the real thing. The brisket was just ok (it was overdone and dry the night we were there), pork and ribs were decent. The beans were blah and the coleslaw has a vinaigrette dressing - I have never been to a Texas BBQ joint that served coleslaw with anything other than a creamy dressing. And finally, in order to keep things just as I would in Texas, I ordered their house made sweet tea (non-alcoholic) - this was the absolute worst. It was full of lemon and barely sweet at all. So disappointing.
The service was really terrible, but my husband had warned me about that so I went in with the bar set pretty low and believe me, they didn't exceed it even though it wasn't busy and there seemed to be quite a few staff around.
The space is really nice (I hate communal tables but that's just me) and I'll probably give them one more try to at least try the creamed corn, but they have a long way to go to be "Authentic Texas BBQ".