I agree with you that this is debateable...but I think the difference is a lot smaller than commonly thought.
Here's some data
From 2000 to 2007, UT had 4 clerks on the Supreme Court. UM had 9, Georgetown 4, UPenn 3, BYU 3, Duke 2, Cornell 1.
Last year UT had 20 students on Courts of Appeals. Columbia 22, Michigan 20, NYU 19, Boalt 13, Chicago 12.
This year UT had 20 students on Courts of Appeals. Columbia 32, Chicago 25, Michigan 20, NYU 19, UVA 15, Berkeley 10, Cornell 3.
For legal academia, UT had placement in 2006 comparable to cornell, Georgetown, Duke, UCLA, Penn, Northwestern, and Minnesota.
In a survey of legal academics, UT's faculty was comparable to Michigan's and better than UVA, Penn, Georgetown, Cornell, Duke, Cornell, and Northwestern.
UT's tuition is lower than any T14.
In a ranking of Law Reviews, Texas' law review is comparable to Michigan's and better than Northwestern, Georgetown, Duke, and Vanderbilt.
In a 2004 list of where federal judges went to law school, Texas is third on the list with 43, behind only yale and harvard.
Currently, the only schools represented on the Supreme Court are Harvard (5), Yale (2), Columbia (1), Northwestern (1). While UT has never had any justices, i think the same could be said for NYU, Chicago, Penn, Georgetown, Michigan, Virginia, and Duke (And I think O'Connor was the only one from Stanford).
Most UT students intend to stay Texas which means that they are underrepresented at higher Vault firms. One study in 2006 adjusted for this an found that Texas sends 2% of its 1L class to V7; 3% end up in the mid-altantic region. Thus, approximately 67% are at V7s. In other words, if you find a UT alumn in NYC, chances are very good that they work at a V7.