dave...... said...
I think you're on the mark.
A Fuel, Vegas, Torch all C kites, C-kite hybrids , RPM, Park, C4. Names that have stuck....
SLE's, Rebel, Switchblade, just about all others dont last more than 3 years...
I think Ckites are tweaked every year, but with the SLE, hybrid, Delta etc, Companies go in a different diection and make these kites way different to the old model they try too hard to make a point of difference.
... ummm Rebel started in 2007 and is still a 5 line kite in 2013 so maybe my maths isn't what it used to be but I think its more than 3 years ... or did I mis-understand your point!