I bought the STARFIRE PEARL. Trust me, I was wowed by the GFM at first glance as well... but the more you look at it, the more it just doesn't quite scream luxury. It becomes like some crazy, not classy, paint job people use to get on their Integras during the "Fast and the Furious" stage. I guess if that's what you're going for, then get the GFM.
Also, I think the initial attraction is at night time, the blue iridescent shimmer just looks different and unique. But that's only focusing on the paint itself. If you took a step back and look at the car as a whole, the GFM is a really odd color and honestly looks like *BLEEP* in the day time. You can't tell if it's like a muddy white, gray, or silver. It also clashes with flat silver rims or the chrome rims. If it was so popular, why is it so rare? I think people view it as a fad color.
Starfire Pearl on the other hand, still has an iridescent shimmery glow to it in day time or night time. And will never go out of style. I would stick to a classic color, not just get the GFM because it's different. If i didn't get the starfire pearl, I probably would have gone with the Obsidian. It's a Lexus, not an RSX. Stick with the classics.
Glacier Frost Mica is the better and rarest color. Before i got my IS 350 i had seen one with the GFM. So i thought it was perl white. When i went to the dealer they had one in their lot and i found out it was the GFM, way better color then the pearl. Most people would like the pearl because the GFM is rare and not everyone is fortunate to get it. GFM all the way.