I only wear my breachen--as a rule--for very formal events. I wear it with a doublet with lace, a jeweled dirk, etc. Strictly for formal attire with a jewled broach at the breast. I don't even have a decent photo of the outfit, but it looks really cool, even on an old guy.

It could be worn quite well for day wear, but I personally would avoid any attempt to make it look like a costume unless it is Halloween or if I am going to a RenFest. With a blut face and a two-handed dirk, it works great for Halloween, and the kids love to see the sword.