I-68 is our "go to" highway to get to I-70 anytime we head that way. The PA Turnpike is crazy in terms of tolls, construction and curves, all in that order.
I-68 is a great road in the best tradition of great roads -- scenic, well maintained (but not congested with construction), easy curves and grades, a great way to get across Maryland with considerably less stress than Pennsylvania roads.
For us, coming from northwestern Pennsylvania, that says a lot because to get to I-68 we have to come all the way south on I-79 to get onto I-68. But, for the above reasons, it is now a no brainer to us if we are headed east to Hagerstown, Baltimore, Washington, DC, points east and south.