From my limited experience:
It's a tad more complex to find a good vendor in Canada. I used to use madvapes, but my friend had a shipment fail at customs. Then I moved to canvape, so the product is already inside Canada. But now I've been having issues getting Canada Post to deliver the package on time. There's almost no point getting faster shipping with them.
Recently I've discovered a small online store based in my city. They will deliver it themselves for $2. I'm going to try that out until I need some more specific parts. They also only sell 6 ml bottles for $4 :\
I've never had an issue getting
juice delivered, even with 18mg strength and 30ml bottles. I think it's just stuff coming from the USA that can fail at the border. Apparently it's hit or miss, and depending on the vendor, you might have to eat some or all of the cost.
The only other thing, which may depend on your town, is that people are completely clueless about e-cigarettes. They aren't against them, but they've just never even considered them as an option.