Like a lot of investors have said - it comes down to your willingness to put in time and energy into these projects, as well as your objectives and goals.
If you have time, energy, and willing to oversee the project - then value add rentals are a great route to go. This also involves a huge learning curve between working with contractors, overseeing the rehab, and ensuring proper progress is made..etc. The best part, is once you've done a few and know what you are doing, it easy to do more and compound your success using your established teams and experience.
Turnkey rentals are a great route to go as well for passive income. The main issue i've found is that most turnkey companies sell at high prices, which really hurts cash flow and the ability to refinance out afterwards. I currently working with a large network of investors to create turnkey investments where you can refi out, and still collect great cash flow and gain better ROI than what most turnkey companies can offer - win win deals for both buyers and sellers. I personally feel unless you have a lot of cash and little time, turnkey properties offered by many companies today offer lower ROI, taking too much profit off the top for the end buyer, and can slow progress to achieving your goal. But, you do not have to deal with the headache of fixing up properties and can begin cash flowing right away.
Whether you choose value add, or turnkey, it is crucial to have a great team behind you. Between property management companies, general contractors, and a third party individual to walk the property and take photos for you. If you ever got stuck and had to pick value add, or turnkey, I would go with the option that involved the best teams to work with, and a route which you are most comfortable pursuing.
Please feel free to reach out to me anytime, I'd be more than happy to talk and share my experiences! Cheers