Be sure your lender is comfortable with this, as many fear giving folks primary loans for properties they view as having a high probability of being turned into a purely investment.

Condo's usually have high HOA dues which will eat into your cash flow.

Demand is very high, both for rentals as well as for sale and this is probably not going to change.

@Nick HulmeMaking improvements to your primary to make it high quality enough to rent above market rents, rent it.

Now that is a very high level example but the appreciation is not gone if that makes sense you will capture the ballpark same appreciation if the properties are comparable.  

Highly recommend

I’d hate to see you walk away from that high an income and regret it.

The 10% vacancy and repairs, along with 5% capex in my opinion are pretty high. 

I agree with @Jonathan Greene that the question is vague, so my advice will have to be as well.The short answer: MTRs are real estate, so just like all real estate, any place that can long-term-rent cash flow with increasing jobs/population can be a suitable site to purchase. 

We have a high saturation of rentals that has caused the market to lose money.