Typically those are built with 4 units to an overall structure. 

Quote from @Jenni Utz: You have that built-in equity on the deals that are off-market.

There’s a real opportunity to hit those $1,500 to $2,000 rent ranges, particularly for updated homes or new construction (built to rent homes) in the right neighborhoods.

While I don't have any horror stories, per se, I have heard of people having a tenant for a year then causing $20k in damages upon move out, while skipping town to not be found again (this was a CA buyer buying from a turnkey operator in AL).  

If you do more than one unit this way make sure you don't need a boarding house license in your town. 

The age of a home is sometimes a misnomer as older homes were built much better in many ways, not all.If you want to flip, you need to focus on older homes because that's where the bigger scale will be most likely and the more outdated cosmetically, the less likely first-time homebuyers will think they can do the work.

I own a single-family home built in 1950 here that I rent out.

They've built a second campus to accommodate nursing and pharmacy students. 

Killeen is a good cash flow market, but you have to buy in the right area and also time your tenant turnover to the Permanent Change of Station (PCS) season since it is predominately military town

Next time I am in town I will stop by and check out your work.