I haven't been on I-79 in WV for many years but the times I traveled on it in the past, it always seemed to be good road and somewhat scenic in places.
I-68 is one of the newer interstates. Nice road, but hilly. It has a number of long grades and some of them will give that Cummins 330 a good workout.
If your schedule permits, take a rest break at the Sidling Hill Exhibit Center
. It's just after you pass through the huge cut at the top of Sidling Hill when you're heading east on I-68.
Of course, I'm sure you already know I-68's eastern terminus is at Hancock, MD where it connects with I-70. I-70 can be a treacherous stretch when wet. I've seen numerous accidents caused by hydroplaning; especially on the section between Hagerstown and Frederick. I traveled on I-70 last February to Baltimore and encountered construction at Frederick. So be alert and be careful.
Have a safe trip.