I'm no partiular fan of Mr. Grylls, and though we have not yet evaluated these pants directly, the pants do appear to present merit.
The construction should be quick-drying, and the knee reinforcements along with the increased mobility afforded by the combination of fabrics should prove nice to have in higher physically demanding activities.
Cotton Kills, and I'll not wear any denim pants in the field - regardless of who the manufacturer is.
The pants would likely be better received if they were simply named "Field Pants", but they, as are any other products carrying the "BG" branding, are marketed to a particular demographic; a fair amount of disposable income, watches/ believes the "Man VS. Wild" show, and chases after the elusive title of "operator" or "survivor" while typing away in the parent's basement.
When performing product evaluation and testing, we evaluate products based on how applicable they are for the proposed use/ environment, durability, ergonomics, ease of use, etc., but not by a particular tag, nomenclature, or person's name attached. As a matter of fact, its not at all unheard of to have a particular item sent for evaluation/ testing BEFORE such title/tag is applied. "Baer" is not a seamstress - he doesn't make these pants anymore than he makes the Gerber knives carrying his branding. Of course, you can purchase the exact same knife from Gerber in different coloration and without the "BG" branding.
The tag that really turns me off the most about these pants has nothing to do with Baer Grylls, but the "Made in China" tag.