For either country, it's much easier to get the proper working visa once you've got a job offer in hand. Moving with the intention of looking for work once you arrive is generally a lot more trouble, as far as getting the proper visa is concerned.
ITA with the above poster. I'm a Canadian who moved 15 years ago to the U.S. and just moved back a few months ago.

We went originally on TN visas. These were very easy, and we just did them ourselves. Then, dh got a job offer in his field, with a H1B visa. After a few years we could convert this to a green card and we used an immigration lawyer for this.
I have a Ph.D. in the sciences from U of T and found it quite difficult to find a job. Many American employers view Canadian degrees about the same as a third world degree.

They've never heard of our universities.
The tax structure is not as friendly as one would think. Even with mortgage interest deductibility, we ended up paying as much in taxes as in Canada. Things like maternity leave are pretty much non-existent. Health care costs can run $1000+/month. IF you have insurance through your employer, you can still be paying $400/month.
We lived in MA and MN. MA was warmer, but too warm in the summer for kids to play outside. Plus there were though pesky Nor'Easters and tropical storms. 100+ inches of snow in one year. MN, we had tornado warnings and watches, blizzards, hailstorms which damaged the roofs of half our neighbourhood and temps of minus 30 Celsius.
Coming home, I found the paperwork to get my health card and drivers license, very frustrating. Many times I wish I hadn't left, just on this basis.
I have 3 kids. Moved back when dh died.

It's he double hockey sticks with the move - which is still ongoing. DS14 is happy to be in Toronto, but wishes he had been born here instead of having to move around.
In sum, the grass is always greener. If you have a job offer where your salary will enable you to enjoy a much higher standard of living, great. But if not, Canada is not so bad in comparison. The job market in the States really stinks right now.