CX-rays do not make a stronger wheel. Strength is the load taken until failure. Who loads wheels like that. wheels fail through fatigue and the rate of fatigue is related to stiffness of the wheel and all the factors that affect that. Spoke strengh plays a small part.
CX-rays may (and I emphasise the may) make a more fatigue resistant wheel but I doubt that as well. The elbow is the is from the same wire stock as the sapim laser or race spoke. Intial strength of the spoke at the elbow must be similar. The data that sapim produce regarding strength showing the Cx-ray to be the strongest is also a bit skewed.
Race spokes strength middle section 1300 N/mm^2 or failure load at 3382N
Laser spoke strength mid section 1500N/mm^2 or failure load at 2650N
CX-ray spoke mid section 1600N/mm^2 or failure load at around 2700-2800N (not sure of the exact cross area but it is around 1.7 mm^")
so CX-rays are not the strongest but they are not bad for a thin light spoke.
the Park tool blade holder is crap next the sapim tool. Much easier to hold and it holds the spoke better too.
I have been using lasers in my own MTB disc brake wheels for years and no issues. Would not hesistate to use them again. The rim needs to stiff though. carbon ideally.
The CX-ray is a very popular spoke for straight pull spokes for this reason. The bend is gone and the sheer forces are changed to a much stronger position. I do agree that he CX-ray will have the same issues as the Laser at the bend, but a properly tensioned wheels shouldn't have issue with that. If so, people would break spokes constantly at the bend, and it is in fact a fairly uncommon occurrence. I do find people get odd about tension though. It is even more odd when I see the tools they use to "measure" tension, and in most cases are pretty shoddy bending tools that can't be calibrated (more likely simply aren't). It is a bike wheel, not the restraint system for the space shuttle carrying a satellite that has the cure for cancer. People have been making them for years, and thanks to current technology, it is easier than ever to make something straight and strong.
Side note, I prefer the DT bladed spoke holder. It has a great design for holding the spoke and still allowing the spoke wrench to turn.