Get these for $60, and thank me later for saving you almost $150:
10W No Error CREE LED Angel Eye Halo Ring Light Bulb BMW E39 E60 E63 E65 E53 E83 | eBay
Like I said it's not about the Weisslicht being "not good", its about the fact that you only get so much brightness from the facelift rings, the optics only allow so much. You could put a 10,00000w halogen in there and it wouldn't be much brighter.
Those will give you the look you need, be bright enough compared to stock, and save some bucks for you.