So why CX-Rays?
No wind-up. Once you've built and trued wheels with bladed spokes you don't want to go back because of their "wrench flats". I'm "industry" and don't pay much for CX-Rays in return for telling everyone to buy CX-Rays.
Ah! That makes perfect sense. Yes, Lasers wind up something fierce. I've learned to twist past my desired rotational position and then counterrotate to take the windup out of the spoke. It's imperfect, but I've had a lot of practice, so it's not so bad.
Also, the fact that you're not paying retail makes CX-Rays a much more reasonable choice. For two 28-spoke wheels, CX-Rays cost consumers a ~$115 premium over Lasers. But if you're not paying an extra $2/spoke for CX-Rays, the convenience could easily be worth it.
I admit it pushes my buttons when people use CX-Rays on mountain bike wheels because they're "stronger" (not true, despite Sapim's scientifically illiterate claims) or, worse, "stiffer." I mean, people can use whatever parts they like, but I find it depressing to watch people extra for imaginary benefits. The low-windup properties of CX-Rays are not imaginary, of course.
Yeah, I've got my eye on that LB asym rim and also LB's 10g lighter, $100 cheaper non-asym XC rim.
Heh. To be perfectly honest, I'd probably get the symmetric rim too. The width at the bead is only 1 mm narrower on the symmetric rim, and the cost savings is substantial.
Have you considered using Extralight hubs instead of DTs? I know pro deals on DT stuff can be fantastic, but if you don't need Centerlock rotors, the Extralights (at least the front hub) might make sense. 68 grams!