They go well with the grunge look. Board shorts, T-shirt, floppy knit cap and Birkies. Yuppies pull them off too. They are a conundrum in that they are amazingly popular, yet nobody wants to admit to liking or wearing them, lol.
I recently got a pair of Columbia Sports sandals. They are kind of like heavy duty Teva sandals with a moulded foot bed for support, and a toe lip on the front to avoid stubbed toes. They are Moss Camo colored with Columbia written in pink, lol. Totally not my style, yet so very me! I love them. <3
If the Birkies serve your purpose, do it! Its not like you are talking about a formal fashion piece afterall.