We drive from Ontario, crossing at Queenston-Lewiston, I190 to I90 to I79, then taking the route you mention, and love this route. Everyone I know also takes this route as it is scenic, the traffic isn't too bad and it's the quickest. The only thing is, 19 is through the mountains in WV, which can be iffy when there is a snow storm, because of the long hills up and down. The first time we took this route, we left from Ontario (about 45 min. south of Toronto) at 4:30 am, and by 8:00 am at the NY-PA border it started snowing, a major snowstorm, and we made it to Pittsburgh by 10:30 am on very bad roads, and ended up getting a hotel there until the next morning. The day after the storm, one lane each way on 19 was clear where the tire tracks went, DH is a very good driver and we didn't have a problem, but he had to be very vigilent. Finally, when we got past Beckley, it was warming up and the roads were much better. We left Pittsburgh at 8:30 am and drove straight through to Ocala, Florida, where my parents were renting a house, arriving around 2 am, with only very short stops to gas up, use the washroom and pick up food to eat while driving. We didn't want to lose a day of our vacation! By the way, thanks sif for the tip about Summersville - we had no idea, and luckily have never gotten a speeding ticket on this route.
Therapy and frequent trips are helping me get soothe my sad inner child. 
