We did that exact thing once, probably about 3 years ago. Exact same flight times.
It is a very very very nice hotel, but definitely for the length of stay (like 6 hours lol) it wasn't worth it. The bed was super comfy, lots of pillows, and definitely more comfortable then sleeping in the actual airport.
If I had the choice to do it again, I would just sleep hang out in the Pearson airport (though nothing is open late, and that is kinda creepy in its own right).
Even though it is at the airport, you still have to catch a shuttle, check in, settle in, and be up super early in the morning to check out, catch the shuttle back, check in with your airline, etc. It just, to me, wasn't worth the extra money. Although, if you have stuff to do the next day, the opportunity to shower, freshen up, and get some sleep might be worth it.
Oh and beware the mini-bar. If your move something in it, it has an electronic sensor and charges you automatically if it is detected.
Hope that helps.