So, I was just looking at the swatch thread and the comparison between Bombshell and Fast Thrill. I agree in the tube they look a lot alike as well as on the skin. But, I just went back and tried Bombshell on the top lip and Fast Thrill on the bottom. There is a noticeable difference, in my opinion. I think that Bombshell is definitely more of a blue based pink. Fast Thrill looks like a pink with a hint of coral in it. Once again, that is on my lips. I love Bombshell and I love Fast Thrill, however, I love them differently. If you adore pinks, as I do, they are both must-haves!
If you just want to try a pink but are not sure if it is your "thing" then I would probably go with Fast Thrill, especially if you gravitate towards the warmer colors, but if you already own bombshell that would probably be enough. Hope that makes sense. Just my 2 cents....