Yes this is an excellent route.
here is another loop that includes most of the popular routes in that area:
I guess you can somehow combine these two loops.
I like this route. The Northern part is fine, but I find highway 50 boring, though efficient. I'd add time to this trip and go along 148 instead of 50; say from Thurso to where you turn North, assuming you are going ccw. Route 148 is slower and the pavement is not as good, but we do ride Stroms. An alternative for this stretch (and my more usual route that-a-way) because I find 148 too slow and the 50 too bland is to go along Ontario Hwys 174 and 17 and cross into Quebec at Hawkesbury. There should be good fries and hot dogs (hopefully still offered steamed or grilled; steamé ou grillé) in Alfred.
Less busy there in Alfred now than when the 17 was the main highway between Ottawa and Montreal, before 1968 or so when the 417 was built. Yeah, I'm old. I lived in Wendover off the highway for several years back then, on the original
17 (which became a secondary road when the newer, now old, 17 was built in the early 50s), now renumbered 55 and silently crumbling away. You haven't time enough to take that stretch. Besides, its rural character has changed to now become yet another bedroom community for Ottawa. There is a nice little stretch which I quite like along hwy 26 (also part of the original
17, but with good pavement) between Jessops Falls and Plantagenet, to break whatever monotony you may find, and it won't slow you down much.
The other route in the original post is fine as well. I take a stretch of it often, and have ridden or driven the rest. Definitely nice roads for our bikes. Watch the speed on the 105. 100 Kph is fine (90 is the limit), and slow down through towns and villages. 120 gets you a hefty fine, and ticket. Don't ask me how I know.