If you are going to buy turnkey I suggest that you actually make the trip out and visit them first. You will definitely want to see the neighborhoods they are operating in and the quality of their rehabs. If you visit these properties in person you may be horrified at the quality of their "turnkey" rehabs. I would also suggest that you look at sales and rental comps of any property that you are considering. Don't ask them for the comps, actually look for yourself. Look at Zillow for sales prices in the neighborhood and look at hotpads for rental comps. You may also want to subscribe to Neighborhood Scout and see about the quality of the neighborhoods.
Some of these guys are advertising properties as A neighborhoods, in places where I would be scared to go into. From what I have seen the rental comps are way higher than neighborhoods seem to support. If they are going to try justify a 1.0+ price to rent ratio they will tend to market it at the very high end of what is possible to rent at and if they can get a tenant at that high rent, they then sell it to you as if this is what you should expect going forward. Which is a misleading expectation. Sales prices also tend to be way higher than the comps in the neighborhood. There may be turnkey providers that offer a better product than what I just saw this weekend in Indianapolis, but this is just my experience from what I saw from a highly recommended, big provider.
In my opinion, it's worth visiting the market you are interested in and have an investor friendly agent show you around the MLS. Most likely you will find a better deal. With sales and rental comps that are in line with what the market justifies. Also you can find independent PM that doesn't have the turnkey sellers agenda ahead of your interest if you do your research. My trip out to Indianapolis was well worth the couple of thousand dollars I spent. Most likely it has saved me tens of thousands of dollars in the long run. I am a pretty new investor, so you can take it for what it is worth. Definitely visit your team before investing though!