Mostly I use the bentshaft as primary and a 9 foot double-blade as back-up (it also detaches into two pieces & doubles as the support structure for my lean-to style tenting arrangement).  If I'm in rough conditions, you can bet the bentshaft will be in my hands... not necessarily because it is better but rather due to confidence that comes with practice.  With more practice, I might feel more comfortable & secure with the double-blade in rough water.  We'll see.

On the other hand, if SPEED is desired & conditions are right, I'll make my time with the double-blade.  You feel like you're flying when you get the rhythm of both those blades going!  It's also a pretty good upper-body workout and takes some getting-used to.

If you are looking for an inexpensive, sturdy, two-piece double-blade option (not necessarily all that "light", however), you should check out Spring Creek Outfitters offerings (see:   (You need to Login or Register).  I went the cheap route just to get started & I'm pretty happy with my selection.

Good luck!

Jimbo   8-)