I haven't actually used Turo, but know someone with a car in the system. Like you say, it is like Airbnb for cars. It sounds to me like you have to find a renter with lots of positive reviews and few or no negative reviews. Otherwise, you're taking a chance. There is a lot less quality control on the cars, and if a particular car somehow breaks down, you will have to do a lot more work to get alternative transportation.
I met some girls at the beach in Maui that used one of these individual car rental places. They had an issue with a Jeep they rented. The owner was very apologetic and came to get the Jeep to get it repaired. Meanwhile, they were without transportation until the owner fixed the problem, where there was severe vibration driving down the road. I think it all worked out in the end.
Just remember you are now dealing with individuals renting their own vehicles. I bet most of the time things work out fine. The issues arise when the car has a problem. There can also be issues of cleanliness and differing expectations on how well taken care of the car is. If you are comfortable with this, you can likely save a bit of money. If you want more certainty, then a commercial rental place might be in order.
I use AirBnB and I am comfortable picking a place with lots of good reviews. I would not stay in one with few reviews, or one that has more than a percent or two of bad reviews. I might be willing to give Turo a try, but will go in with my eyes wide open. I'll likely make a Hertz reservation on the side, just in case. I get good corporate rates with them.