Hmm, ya think there's a difference? Old is a neon coral, and newer is much lighter, and looks peachy (I haven't tried it yet). Both are bright! FFF seems like it suddenly got a huge uptick in popularity when the new one came out, but that just might be because it then became part of the core retail displays, and thus was much more easily available.
China Glaze Thistle Be the Day (also untried) seems VERY similar to the old FFF, but pinker. I loved FFF when it leaned pink, and not so much when it leaned orange, so who knows, Thistle Be the Day might replace it in my heart. Which would be good, since it's halfway gone.
The new China Glaze Pool Party (the old was a neon pink; I'm not sure if the new one even counts as pink, or what color to call it to begin with) also seems kind of close to the old FFF, like old FFF is the middle point between new Pool Party and Thistle.