I'm in Kevin's camp. If the dust is being adequately picked up, then it's a winner!

I should mention that I, too have a Felder K700 series saw (the K700S, to be exact) and have also produced my own after-market above blade set-up. Like Joe, I started with the stock blade guard, but in my case I merely epoxied into place a bushing made from a short piece of 2 1/2" plumbing drain to enable me to mate the guard to a 3" flex hose. Yep, I only have a 3" flex hose acting as my above-blade dust collector, and I'm very impressed with how dramatically it's improved things. Is it perfect and does it pick up all the dust? Not by any stretch of the imagineation, but then it's met my objectives of removing the vast majority of the above-blade dust, while allowing me to retain the narrow profile the stock guard provides. The only thing I think I'd consider adding would be one of those broom, or whisker sets to the sides of the guard which would close up the gap more effectively.

I should mention that I don't have anything other than my Mark 1 eyeball to tell me how effective the new arrangement is. I'm happy.

Here's a few photos of what it now looks like:

Above blade photo.jpg

Above blad1 photo 1.jpg