Both look good. The grandprix is 15 grams lighter at 205 grams.
Read some reviews saying the grand prix have weak side walls but that they roll better/are faster than the gatorskins.
What do you think?
gatorskins are super sticky and durable, my favorite rear tire by far, however i cannot say much about the grand prix. but is the extra 15 grams really gonna hurt?
dj: 09 eastern night train 26
fg: volume cutter 2nd gen w/ spicer track fork
bmx: fit dak build
Assuming there is no skidding involved, both tires will last many thousands of miles with normal use and wear. The GP is an amazing long-distance tire, but the Gatorskin does afford you a little more durability and resistance to slashes that will end a tire's life. Another option is the GP 4-season, if you are looking for stickiness or tackiness. The 4-season is my favorite road tire. Price is also a factor, and the Gatorskin is cheaper.
I've gone through 2 GP4000's in the time it took to go through one Gatorskin. The ride is so much smoother, grippier and more pleasant it was worth every penny... even with the occasional flat.