Personally, I would sell and put the money into a no-load investment fund. Of course, I really don't want the hassle of dealing with a rental property which colors my decision.
I know many people who sold their rental homes in the last 2-4 years that missed out on life changing wealth. If you hire a good PM it won't be a hassle.
Here's one of my homes based on Zillow in the last month.
Home value
Zestimate
$209,200
Zestimate range
$197,000 - $222,000
Last 30-day change
+ $5,374 (+2.6 %)
Zestimate per sqft
$186
That's basically double in four years.
The other homes are up $9k, $10k, and $2k. All are cashing flowing so my tenants paid me to put $26k in my pocket in one month.
My opinion is that if you own a home or rental property do whatever you have to to hang onto it. More so if you are paying 2.5-4.0% interest rates.