I purchased a pair of the Wiley X Bi-focals last summer. They are great. Period.
Purchased them off the web using the 'standard' bifocal distance. I would consider (if you wear perscription glasses - especially bi-focals) to go ahead and find a professional that can fit/measure them properly. Mine are just a 'touch' high (the bifocal line), but I've adapted.
For me, the overall quality and fit to my face were great. Keeps the wind out; great optics; keeps most all of the intense sun rays out.
Tex