Thanks all for your contributions.

Interestingly, a colleague of mine has just applied for one - they are a British citizen who spent some time resident in Canada as a child due to parents' work. I do not know what visa they held but I assume it was off the back of a parents' work visa.

They got an e-mail saying that their application was being reviewed and they should hear "within 72 hours" regarding "next steps"... 24 hours have gone and no contact.

So this aspect seems to be pretty poor, at least from a Customer Service perspective. Some people might be tempted not to bother and take their tourist dollars elsewhere. It's a fine line I think between security and deterring legitimate tourists and their money...