Hi there,
My wife is American and we grappled with this decision before we applied last summer. We ended up applying via Outland.
As a US citizen, yes, Outland is definitely the way to go. Though it fluctuates, US citizens are typically getting approved in 5-8 months by Outland, whereas some people have been waiting nearly 2 years and counting via Inland. Especially if you live in New York and she lives in Ontario (I'm making assumptions here), outland is far and away the best choice.
You can definitely visit your wife while the paperwork is being processed. In fact, though we applied outland, my wife essentially lives with me in Canada. She is on a visitor visa which she was able to easily extend for an additional one year (past the standard 6 months Americans typically get when they come into the country). The catch is that my wife is not working or going to school during this time, but at least we are together and financially, we are able to live off of my income so we are lucky in that regard. When my wife is approved for PR (soon hopefully), she'll return home for a visit, then come back and officially "land".
Currently, my wife can leave whenever she wants, and she should be fine to come back in. However, if she leaves, the 1 year tourist visa extension will be voided. That doesn't mean she can't come back. Many people here talk about "circling the flagpole", essentially going to a border crossing and "resetting" your 6 months, but we haven't tried that ourselves. Apparently with your case number, this process is much easier, but I'm not sure.
On the other hand, if you apply via inland and you leave at all while your application is processing, it is voided. That means for at least a year and probably closer to 2 years, you cannot leave Canada, even for a family emergency back home, or your application is toast. The only advantage of inland is being able to get a work permit but even that won't happen for about a year, at which time you will probably already be approved if you apply via outland.
I hope that helps!
