Gene,
Looking forward to your visit, though you may wish to leave your license at home. My dentist acquaintances tell me that this is an extremely competitive market. And with 4" of snow on Saturday followed by 80* with 40mph winds yesterday (Thurs.), the weather is not at all that pleasant.
I am embarrased to admit that I have not played La Cantera, Onion Creek, or Austin GC. I used to practice at Onion Creek while working in Austin, but the course was not considered anything special so I never took the time. Ditto for La Cantera. I've been trying to play Austin GC for a year, but so far I haven't been "invited". The noise on the street is that it is rustic, very exclusive, but not top shelf. Spanish Oaks, nearby, is a course I like very much and has received wide acclaim.
In thinking back about Texas courses with outstanding starting holes, I am coming up with blanks. Most are too bland, or too hard, or not representative of the course. Even Dallas National starts out really slow with what is probably one of the least interesting holes on the course.
I guess that my candidates for Texas would be Spanish Oaks, opening with a mid-length meandering par 5 into or quartering the prevailing wind, with quite a bit of elevation changes from the tee to the landing areas, and back up slightly to a well bunkered green. The other would be at Pine Dunes, a mid-length par 4, DL R/L, with a deep, heavily contoured green falling of at the back.
BTW, I doubt that C & C set out to make a statement with SHGC's #1. But if one was writing a book on designing ideal starting holes that one ought to be on the cover for the reasons you stated. I am not good at remembering holes that I haven't played numerous times, but that one is clearly etched in my mind. It is a microcosm of the course, and a fantastic invitation to what a great experience follows.