Since your spouse is already in Canada on a visitor visa, Inland Spousal Sponsorship is more appropriate. It provides the benefit of living together in Canada during processing, and your spouse can also apply for an open work permit if eligible.
However, it’s important to note that if your Inland Spousal Sponsorship application is refused, you cannot appeal the decision; you can only reapply. In contrast, an Outland Spousal Sponsorship application can be appealed if it is refused.