I know the post is older - but right now in Vancouver anything better than a 3CAP seems to be amazing. Depends on your play. If you buy at a 1.5CAP, but through "renoviction" can bring it to an 8CAP because of the property needing work, upping rents, and increasing efficiency - that's gold right now.
Depends where you are. As an investor, and realtor in Victoria (Royal LePage Coast Capital Realty) - I've actually found that the CAP rate you buy at isn't the sole reason to make or break a deal. For example I know a fellow investor who buys at 3CAPS all day because they can evict, rehab, and manage well enough to force the CAP rate where they want it.
There have been a lot of rule changes with the tenancy act, and as of TODAY the way realtors do business.. so be picky about who you work with.
I know that was long-winded and a bit general - but it really boils down to "It depends".