I have used one pair of these gloves for nearly six years. Yes, that's right. I bought them in a L in a little shop in Indiana. I've ridden them in Texas summers, Moab winter/spring, and every season in Wyoming. I'm a teacher and I spend most of my summer on my bike riding aggressive All-Mountain trails and granite filled XC so they've taken their due punishment.
My gloves fit pretty snug-but that could be from years of sweat and washing now. The polycarbonate knuckles have never bothered me and cradle my knuckles perfectly enough I don't think I would prefer separate knuckle protection. I ride 820mm bars and the 'knuckle duster' has saved me some skin plenty of times. When the polycarbonate plates does its job, the impact/abrasion is mitigated without any discomfort to the hard (obviously I'm not talking about hard falls directly to the hand & wrist). The leather in the palms is strong and shows little signs of wearing out.
I've had no issues with the stitching on my gloves nor the Velcro. The palms are double stitched and the majority of the rest of the glove is single stitched but I have yet to notice any fraying or blown seams. This makes me wonder if there aren't some cheap counterfeit products floating around...
Let's talk about breathability. They're made of pittards leather and polycarbonate. I don't know of much leather that "breathes well" and these are no different. If this is your only glove (like me) and you're wearing them on an 85+ degree bike ride it's going to be hot--just like the rest of you and your sweaty gear. I've ridden these soaked through with sweat and the only issue that arises is the tacky tips on the index and middle finger no longer stick. When dry, these tips stick like 5.10 rubber on pins.
Sizing: find them in a store and try them on if you're worried about the fit. Or buy them here and return them if you don't like the fit (backcountry has truly amazing customer service) but don't down-rate the glove just because it didn't fit right the first time. They're gloves-expect less sensitivity and a light loss of dexterity--they're called "bomber" for a reason and if you're looking for light, breathable, excessively tactile these aren't going to make you happy. If you need something you can wear and beat to hell-you'll love these.
All of that said, it's time to buy a new pair. Why? Well because these ones smell so damn bad. I wash them and one ride in they smell like an unholy abomination again. So they'll be retired to the emergency bike gear box in the truck. Yup, the smell is that bad. But considering they're still functionally sound and have endured the abuse they have, I will without doubt buy the same pair again.
For the record-I've never been unimpressed with Fox quality.