Albertan,
I have used both in my KX250s & pleased with both. You get more with the VForce, but you also get a lighter wallet. It sounds like you have a K5 (ZipTy Pipe) & if you don't mind spending a bit more get the VForce as Stewart on this forum has done all of the testing on all of the different reed blocks. I purchased my K5 VForce (2 Series) from him directly. Shoot him a PM & it will be on your doorstep this week & it helps all members here on the forum.
DoldGuy