Many investors seem to take the approach that a PM is just an unnecessary added expense that they can handle themselves, but I know from experience that a great PM will usually rent your property more often, for more money...not to mention take the daily management grind off the owner's plate...freeing them up to do more deals!  

It works well if you have a good generator and can tolerate the annoyance factor of the noise, the lugging of the generator, and the buying of the gas.

Most people prefer it, and reduces noise considerably... plus it's cheaper.

Other things to look for in either scenario, but potentially even more so for flipping, are things like the walkability of the area (can people walk to things like bars, restaurants, coffee, school, is it very hilly or is it a pleasant stroll), ratio of owner/occupants to renters in the area (people like to buy where everyone else buys, not in high rental areas), street noise (people like to have easy access to the highway, not be underneath it), etc.Of course, while internet research is hugely beneficial, a great way to know if a property is a good bet is to visit it and tour the town yourself.

Personally, I've turned down many rentals just because of the train noise.

The problem is the highway noise from I275.

The house is under a flight path and it might provide noise insulation as well.

@Eric Barnett There is a meetup held once a month at the Grind house coffee shop in Kyle which serves Comal and Hays counties.

Challenges could include:Having the population to make it a sustainable day-to-day venture.Finding quality staff is tough these days, don't care what you pay them.Breakdowns/serviceInclement weatherPennies on the dollar at exit If the truck does say, 1000 bucks and after labor/cost of goods the operator's left with 500 - 600, then has commissary expenses and a possible split with a partner(s)Ehhhhh...burnout.There were dozens of trucks here 5 years ago and only a handful have really survived the grind. 

Check with the local town regarding noise ordinances, parking, loitering, large gatherings, etc.