I have jumped a Stiletto 97 for years now, and the C99 is a very comparable canopy. The first thing I noticed, when packing, was that it has a differential line set. Each line group has different line lengths, as opposed to all of them being the same. Instead of the parachute being arced over your head, it is fairly flat with only the wingtips being drooped for more lift. I trimmed my Stiletto like that over a year ago and noticed a radical inprovement in the lift and glide.
Openings are great of course.
They are a little more progressive than the ST97. The glide is flat and shouldn't be too stressful on long spots. The input range is longer than the Stiletto - it requires significantly more input to get the same response, but the trade off is obvious when you flare. The stock brake setting makes the flare feel way deeper than you Stiletto pilots might be used to, but in a full-on deep front riser turn, the brake lines are taut, but the canopy is flat and unencumbered by any tail deflection. The Crossfire dives more than the Stiletto with a longer recovery arc.