Many years ago I bought two pairs of Craft boxers. Both of which I still have and still use. They were great and have certainly lasted.
However, and it's a big however, these new ones aren't great.
I needed new pants and went for these expecting simply an updated version of my old ones. Unfortunately this wasn't the case. The material is much thinner and lighter. Initially this felt a good thing. In theory I'd expect them to be more breathable, and on first wearing almost felt silky to the touch. They felt great to put on and very light weight.
The problems started though once running. Within minutes all the leg material bunched up in to my crotch and felt uncomfortable. Then a few miles in it felt that the material, now warm, loosened and any support was lost. So much so that the 'bells and whistle' began trying to escape; not the most comfortable way to run.
If you want some light and breathable pants for regular day wear then by all means give these a go, but I wouldn't recommend them for running.