I've tested both extensively for a European audience, and IMO Toronto wins for UK/DE routing. Take it with a grain of salt, YMMV.
My methodology: spun up identical boxes on Vultr Toronto and Hetzner Vancouver, ran mtr to London and Frankfurt for 72 hours. Toronto averaged 18ms lower to both. Vancouver's advantage is Asia-Pacific, obviously.
The catch? Both providers might be anycasted through Seattle anyway. I haven't verified the actual fiber paths — https://bgp.tools