I think OPP's stricter in SW than in Eastern.
Going down the 401 west of London, every now and then, I see signs telling drivers the speeding fine for each increment of 10 km/h over the speed limit. On the other hand, in the east, I only see it at Napanee. Technically there's one east of Cornwall but that one's expected because you're coming into Ontario from another province. But that's only the 401
The other places where I see that sign in eastern Ontario are 17 near (but southeast of) Renfrew and around Alfred (in Prescott & Russell).
In SW, on the other hand, I see those signs on 24 (between Brantford and Waterloo) and on 6 (at Southern Bruce Peninsula).
Maybe I'm just biased.