I look at mine as investments but I do have one in particular I do use occasionally for personal use. 

If you can, visit the property occasionally to check on things.

He also talks a lot about gap funding or seconds so those we know will blow up occasionally. 

A way around the whole issue is something we occasionally consider.  

You still have to add chlorine occasionally and I find it fussy.

But occasionally we have issues and tenants need to be asked to leave or just decide to disappear in the middle of winter and it sucks.The worst part is I find the quality of tenant interested or willing to move this time of year isn't the greatest either - often times there is a reason they have to move right now since most landlords don't like ending leases this time of year.Either lower your rent or just hang in there.

I cannot specifically think of any issue at all but occasionally we have had complaints about something clearly listed and when we point them to it the complaining usually stops. 

We try to save money by occasionally doing our own work, we only have a handful of properties.

Prices a few years ago were based on expectations of (in addition to interest rates staying low): - Then current operating cost assumptions (like insurance cost expectations being flat)- A seeming disregard for record levels of new inventory / supply hitting the market- Extremely high inbound migration expectations which are likely to not be met, due to both natural disasters and the boomerang effect when people from California or the Northeast move to the American South and hate every minute of the humidity, the large and relentless swarm of insects, and the occasional hurricane. 

Occasionally there is some decent Savings in those relationships as well.