Flew into Love Field last weekend with the flight path directly over Dallas (too low, IMO!!). It has a well developed downtown area with public transportation.
Contrast that with ABQ which has mostly government offices and/or empty old buildings downtown. Most of the office type businesses are along the interstates -- I-40 in Uptown, and now I-25 by Journal Center. I can not see a way that this is going to succeed, IMO.
As much as I am a railfan, I can not support something so ill-conceived and ultimately costly. I see this and the governor's "space-port" as becoming financial thorns in the governor's side, which I will be glad to point out to interested parties.
ABQ is just not large enough to support rail.
In Dallas, the light rail, with off peak service at 20 minutes, and peak spacings at 5 minutes or less, has been sucessful (but still doesn't move as many folks as one lane on an interstate). The TRE, which ABQ is trying to emulate, runs at about 2 hour spacings, and has no Sunday service at all. It does seem to be fairly successful at rush hour for commuters, but it isn't really viable for getting between the two cities. The light rail has also proven to be a development magnet, the heavy rail has not.
As far as Dallas looking vibrant, the west side of downtown is in pretty good shape, but the east side has a number of vacant high rise buildings. Plans are fianlly moving forward on demolishing several of them and converting others to residential, but I could easily find you 3 or 4 empty buildings in the 15 - 20 story range, and could probably find you something larger if you didn't mind a few occupied floors.