I'm in the same boat. It seems to me that the biggest advantage Duke has over Texas is the hiring the summer after 1L, but that doesn't seem to be important to make a decision; I doubt that UT 1Ls are working at Whataburger over the summer.
It does seem to me that when people ask me where I got in, Texas rarely gets much of a response, but Duke usually gets an "oooh," which is nice, but it's hard to base a decision on that as well. It seems to me that if you do want to work in Texas, Chicago, Harvard or Yale will have an advantage over UT, but the lower half of the T14 doesn't seem to have much of an edge. Then again, this is all based on information I've pieced together from this site, and much of it is conjecture I'm sure. But I'm really feeling the prospect of 3 more years in TX more than some layman prestige.
PS - Did Duke send out a flash drive to everyone they accepted? Or do you have to be a supercool 170+ applicant? This favoritism might be the nail in Duke's coffin for me.