[northwind]

Probolts are OK for what they are- cheap anodised ally. They're not very strong at all. I use their engine kit because I hate the "stud" look you inevitably get with stainless on black. They're generally a hassle- they can shear off before reaching the recommended torque (though they're easy to extract at least). I did have more of their stuff all over the bike but gradually I've gone to stainless (Chewy's kit, plus a couple of Ebay bags of mixed bolts for the nonstandard bits)

You certainly couldn't use them for any safety-critical position- brakes, for example. And I reckon it would be a good idea to be generally accepting of the possibility of a sheared bolt.