Running Toward the Light

Over the past few days I think I've read every post available on the 'fest, on M3 Post and E90 Post regarding replacing the stock halogen angel eye bulbs. Now that I've done my research I have some questions:

1) It looks like there are two major ways to go - either replacing the halogen bulbs with bulbs that are blue coated to shed the "white" light. ie - GP Thunders and competitors

and

2) Replacing the halogen bulbs with an LED bulb ie Angel iBright - Lux H8 - Weisslicht.

I know that the LED replacements are a lot more expensive.

The M3 guys all seem to love the Angel iBright setup ($300), and from what I've seen in photographs, this appears to be a pretty close approximation of what I remember seeing last summer when they had an LCI E93 on display at the Welt.

Yet, when I read the fine print of the sigs around here, it seems like most of the E9X that have made this modification have done so with the GP Thunders. ($20)

1) Is cost the only reason people aren't doing the Angel iBrights?

2) Are the GP Thunders really that good?

ps: E92LIghting, JLeviSW and EAS - I know you all are going to show up here and try to sell me. I've already studied your websites and your products. What I am looking for here is real time - real data from the day to day users.

TIA