A qualified recommendation is Austin Proper Hotel. I say 'qualified' because you won't get points or nights counted here (the Prosper chain must be one that doesn't do the full Bonvoy thing). As Titanium, I did get an upgrade and late checkout for my recent August stay, though. There are several Prosper locations in CA and I think Austin is the first one outside CA.
I'm a native Austinite and really like this new option due to the great staff, amenities and location. It just opened this year so they're trying to make it all work for guests! I think they have a great concept.
For a great sunset view, try drinks at P6 at the Line. Hope you have a great stay!