Zipp Vuka Stealth is what I bought after comparing to the AlphaX.
from what I could find out it is a stiffer and higher quality bar. Delivery at the time was also a lot better.
Looking at the Aero data on the Tririg site, I noted that they compared the Tririg to the Zipp Vuka Alumina which in my opinion looks to be a far slower bar to the Zipp Vuka Stealth, Vuka Aero and the TriRig AlphaX - not even a comparable bar. I was very suspecious about the aero data and decided that there is probably a very good reason for them not being compared and I suspected that the Vuka is not a slower bar.
TriRig aero data:
http://www.tririg.com/...mp;page=windtunnel_2 Zipp Vuka Alumina:
http://www.zipp.com/...ik8tfmw10cl7b84d87t4 The Zipp also has a reputation for being very comfy on the pads, and it is.
That said, the new TriRig Alpha1, assuming the quality and stiffness is apparent, looks like an excellent bar and worth a look. It looks like they have used a similar single post design to the P5X, still using the same large Kammtail aero profile as the Vuka Stealth, integrated stem and very flat as expected from TriRig. Also bloody expensive like all top end bars.
http://www.tririg.com/store.php?c=alphaone