I'm not experienced with I-80 across PA, but I have driven the turnpike numerous times. I suspect the scenery is similar along both routes. The turnpike has recently been improved, I've read, so that it no longer deserves the reputation of being one of the most degraded interstates in the country (since the late 90s). That's what I read, anyway, on the state's website.

In PA, I'm much more likely to get off the interstates and use the other main roads wherever possible, although that does cost you some time (although maybe not as much as you think). I'd do this because I really enjoy two lane roads and the less hurried travel possible on them. It's always easier for me to slow down and relax if I'm off the interstate.

I looked at road construction on each route, and I counted 6 sections on each of these routes under construction at the present time -- so greatly depending on what the delays and lengths are, that seems at least like it might be a wash.

Grab yourself a good paper map, fairly large scale, and see what attractions lie along each of these routes, then choose accordingly. You can also pull up PA's website -- most have an online presence -- and see what you can find there. Others may weigh in here with more specific information than I can provide, so also keep checking back for additional responses. Welcome to the forum! Bob