35 knobbies vs 28 slicks for summer roads

[kat_h]

I'm wondering if it's worth changing my tires for the summer.

Currently I have 700x35 knobby cyclocross tires, which have been great through winter and spring, and for gravel roads. Next month I'll be doing the MS Tour (180k over 2 days) and in July I'll probably be doing a couple of short, unsupported 3-6 day tours. Am I going to notice a huge difference if I run slicks for those? Some days I still like to go down gravel roads or even join in with the mountainbikers so I'll still have to change back to my knobby tires once a week or so. Is it worth the hassle to run slicks for the longer road rides?

I just realised I put this in the wrong area. If a mod notices it could you please move it for me? Thanks.