Roar at SFA and Roar at SFDK are very nearly the exact same ride (the stations are oriented a bit differently, but other than that...). SFA has PTCs and SFDK has Millennium Flyers. Not to say that either of them is anything to get all excited about, but at least at SFA, you can find a couple of seats that ride decently. At SFDK, 4 rides in various places on the train were enough to tell me it's just not going to be fun no matter what.
Voyage was engineered with PTCs in mind. It's all that was available at the time for Gravity Group engineers. I've had mostly great rides on it and a couple of roughish ones. Even the roughest rides I've had on it were not as jarring as the Grizzly at KD, and certainly not as rough as Roar at SFDK or Wildcat at Hershey. Now that I think of it, I rode Wildcat when it had PTCs and again last year with the MFs. The MFs made a marginal improvement, but not enough that I could pin it's roughness directly to the presence of PTC trains. It is still a really rough ride and, like the Voyage, was engineered to run with PTC 2-bench trains.
As far as the future addition of Timberliners to the Voyage goes, we don't know yet how they are going to actually affect maintenance or how it rides. It may be that with as large and aggressive as the Voyage is, it will always tear itself apart regardless of what kind of trains it has. I'm just thankful that Holiday World invests in an amazing woodie maintenance crew to keep all of those coasters running well.
