Getting a hotel is definitely doable for 7 and 12 hour layovers. The flight from YYZ arrives at 13:29, and the immigration lines to enter Panama should be quick. So should immigration and security back into the airport at 8-ish.
Only hotels near the airport: Crowne Plaza and Riande. The Central America thread has several posts about hotels and layovers at PTY.
The "worth" of doing so is up to you. Dining options at the airport are limited: fast food + 1 sit-down US chain restaurant. And the Copa Club is weak.