Brandon,
really, you shouldn't base which you get solely on what people here prefer. everybody is partial to one or the other...well, most are. for every awesome pic of a jungle, there is one of an IJ (see Yasser's IJ's and Jeff Favelle's JCP's). I personally own 2 IJ's, so for me I am partial to them. I PERSONALLY find them to be extremely docile, calm, hardy, and eat well. Mine even started on rats which is pretty difficult to get a carpet to do. For me, the more earthy tones (dark tan-brown-black and gold-yellow)are more pleasant looking, but for many others such as Jeff F has suggested, the black on yellow is better. It's all personaly preference. As far as which is more nippy, it's probably true that they are somewhat equal, it's just that in MY OWN experience with both species (I own IJ's, and my buddy own's JCP's), I find my two IJ's (and his one IJ), to be more calm then his four JCP's. Good luck. Both species are wonderful, and you can't go wrong with either. If you go IJ, it's easy to find a breeder that can show you through records that the snake is captive born and bred. good luck
MIKE
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1.0 Reverse Okeetee, 0.1 Albino Snow, 1.0 Irian Jaya Carpet Python