I normally clear us customs in Vancouver so this will be a new one for me. Perhaps a stupid question but my bags are checked directly to final but I have a long 6 hour connection in YYZ. I assume I can go landside and come back through regular us cbp at Pearson without claiming my bag?

The UP Expresss train will take you to downtown in half an hour. Buy round trip and you will save. It’s quite a nice ride.

Once you get off at Union Station, you are within walking/ cabbing distance to various sights - I recommend St Lawrence Market and if you must, CN Tower (kinda lame to me though). The Distillery District is nice but you will want to take a cab. Do not cab anywhere during rush hour (7-9AM and 4-7PM).

There’s a 7h or so RT over a generic return that saves even more I believe. Just had to be used within 7h or so which will fit your needs.

Remember at times there can be a bit of a wait for UPX so leave 45-60 mins to get back to YYZ once you arrive at Union. Also Union can be a maze if not familiar, especially with the continual construction.

Suggest leaving at least 60-90 mins for US CBP. I go for 90 without nexus and a NA passport. It can be busy at times.