trs80 wrote:

So any way, I was wondering how much performance I lose by going the 4" vs
6" route.

For 30' of straight pipe, one wye, and 6' of flex hose, the 6" gives
2.25 inches of pressure, while the 4" gives 3.57 inches.

Whether the additional pressure is a problem will depend on the fan
curve of your blower, hood losses, separator losses, filter losses, etc.

Chris