I was looking at the new models on LS website and noticed 2006 Vortex (non sloping) and the 2006 Ultimate really look alike. In fact, other than the downtubes that are in the opposit direction, everything else looks identical? What other differences are there between the two? Maybe the stays are made of different grade ti?

Pics courtesy of competitivecyclist.
<img src=http://images.competitivecyclist.com/images/products/litespeed/2006/vortex_zoom_1.jpg>

<img src=http://images.competitivecyclist.com/images/products/litespeed/2006/ultimate_zoom_1.jpg>

Vortex: Available as standard or compact frame, all 6/4 Ti

Ultimate: Standard frame only, 6/4 top tube, rest 3/2.5, shorter chainstays and wheelbase.

Source: LS website

Traditionally the Ultimate and the Vortex have had different geometries. The Ultimate was the crit bike and the Vortex was more of a stage racer. That could be changing for 2006 though.

Vortex: Available as standard or compact frame, all 6/4 Ti

Ultimate: Standard frame only, 6/4 top tube, rest 3/2.5, shorter chainstays and wheelbase.

Source: LS website

Which is stiffer?

road both, and I ordered the vortex compact, man what a great ride. I went with the reg. durace build (not pro) and upgraded the wheels to SL and seat to arione. The difference in the down tube makes a huge differance when it comes to stiffness in certaiin areas. The vortex is a great sprinter and climber. All Around Great Racer.