The Koxx sticky tyres are sticky and very grippy, excelent for natural (heard there good for street aswell though), they wear down realy quick on street though, they also have a tread that releases all the mud for extra grip in wet conditions.
The Maxxis creepy crawlers are aslo very grippy and good for natural and street, i've been running mine for a few weeks now and have worn down little but are cheaper from places (Y) compared to the koxx
i have run both sets of tyre but honestly can not decide on what are best, i recon either one of these will be awsome :)