Nothing really wrong w/ my SPIs. I just haven't ridden anything else in the last 6 years and thought this was a good opportunity to try something new out. I've heard great things about Unions, so thought I'd give them a try. The Chargers look sick, but they're also pretty expensive and I wonder if they may be too stiff to combo w/ my PYL. I'll probably be taking that out on deeper days and into the trees. Obviously they work for at least one very successful snowboarder...
Nivek - I don't really know much about K2 bindings so I'll definitely check them out. I guess it makes sense that their bindings would be a good fit for their boots.
Generally speaking though, I could see why a very stiff binding would be good for carving groomers and a very flexible binding would be good for freestyle, but what is the best flex for freeriding? My gut tells me you want something that is stiff, but torsionally more flexible to take all the unexpected bumps in stride.