Soliciting negative opinions about a knife you claim to really enjoy seems an odd exercise, but I'll bite.
I dislike big butts and I cannot lie.. that flared butt-end of the handle, while I'm sure is quite comfortable, looks like (combined with the pocket clip placement) it would take up too much real estate in and around the hem of the pocket for my preferences. The Project X's large posterior, along with the pronounced snag-point.. err, sharpening choil.. in the blade has kept me from ever seriously considering buying one. I think the blade shape itself looks great, but the overall design seems a little unrefined to me personally, compared with the XM-18s/Eklipses/Firetacs. Idk.. I'm sure it's a very well-made knife, and if you really like it, that is great .. but it's got enough going against my preferences that I know I'd never carry it over so many other knives.. and so I will probably never own one haha