What should I do with rental property

Just wanted to get some opinions on what I should do with my old condo that is now a rental property for me.

It was purchased for $150,000 back in 2003 and was my primary residence until 2014. Since then I’ve been using this as a rental property. The condo is fully paid and I can get net about $1400/month after condo fees, property tax, etc.

The condo is now valued at about $320,000 and it has not appreciated much in the past 10 years. I’ve been contemplating selling it to pay off the mortgage on my primary residence. I have about $230,000 remaining on this and on a variable rate mortgage (prime - 0.95).

What are your thoughts? Sell and pay off my mortgage or continue to keep as a rental property?

TIA