I've had three of them, one of the 1st batch that they ever made, a MK2 and a MK4? -pre EBB. Loved all of them.
Nice pop-able manual roll kind of bike-bought the 1st one as apart from the Spooky Metalhead (which my brother had) they were the closest MTB frame to enable you to ride it like a BMX.
I only sold them on as they dented quite easily (as does any ali frame I guess) especially riding up in Lee Quarry a lot.
Now ride a Bluepig but I miss the Cham handling-the 'Pig is more of a plough through-stick to the floor bike compared.
The Cham is a lot stiffer, in areas where the back end would start tankslapping at speed the Pig is more settled and does take the edge off. Awesome punch though out of tight berms/corners-never matched by the wind it up to speed 'Pig.
original spec '97 MK1 (note the '98 Z1's)

Dirt Jumper forks spec;

MK2/3 Hack/winter bike spec (with those original Z1's)

Same again but stripped an polished upgraded spec;

None of the Mk4 (didnt have it long enough!)