i've got continental gator skins both my road bike and my wife's commuter. a bitch (like all conti road tires) to get off and on the rim, and seem to wear quickly in crap weather, but they're way lighter than marathons and seem to resist flats just as well. comfi for their size, too
I am running Gatorskins 25c since new years, no flats at all. Should have sprung for the foldable version for easier swapping i think. I haven't noticed the wear issues, but I don't ride in the really nasty weather. Heard the Maxxis refuse are good too.
From experience, 28c road tires just will not be fun for any extended distance on gravel trails. For a mixed surface commute like the one you mention, you want a cyclocross bike (with discs preferably), running 35c low-profile/fast CX knobbies.
Steed has the 2013 Specialized Cross Disc for about $1300 sticker price right now. Sora level gruppo though.