From CDave's site:
Most that have tried both the Boyesen RAD Valve and Delta Force Reed Valve on the KDX prefer the Delta Force.
That was my take on the two. He
does say most, not
all. Words mean things.
The biggest 'bang for the buck' would probably be the aftermarket Boyesen reeds (fiberglas or carbon) on the oem cage. That's due to the 'buck' part being a low figure.
The whole idea of 'bang for the buck' diminishes after awhile. The more money you spend, the higher level of modification your bike is taken to, the more bucks it takes to get not much of a bang at all.
Gee! There's a rocket science statement for 'ya!
If your point of view is 'bang for the buck' you would probably be better off simply maintaining the bike you have.....put your money into effort, grease, bearings and fuel.
If you just like to tweak stuff and therefore are simply curious as to what works better than something else (according to 'most'), then comments posted regarding one type of reed vs: another will be of interest to you.
For about the gazillionith time, please recognize that the DeltaForce reedcage is
not the same as the DeltaForce II reedcage. Besides being completely different, they also are not at all the same.
Go figure. ;)