Anyone use other than cap/phillips screws in builds?

[Thorsteenster]

I was ordering a couple bits from McMaster and got to looking through their hardware and ended up ordering 50 stainless 3mm X 20mm hex head screws, washers, and locknuts. I got the 20mm ones because they are fully threaded so I can cut to length.
I don't know how big the hex is, but the "mini bolts" ought to look pretty cool.
Anybody else used these before?

Typically I order screws and nuts from http://www.microfasteners.com but they only have the hex head screws in SAE sizes.