Hi @Jey Berke, I'm an investor in a couple DSTs, one in FL and another in KY. I was fortunate to find @Leslie Pappas here on BP and she was extremely helpful is guiding me through the process. She also wrote a book on DSTs that is easy to read and a really solid resource, if you reach out to her (send her a PM) she'll most likely send you a copy.
Regarding returns, I look for cash flow that starts around 5.5% and increases each year from there. This has been my experience so far. When the sponsor sells the property you get the appreciation, so typical historical returns of reputable companies are in the neighborhood of 10-15% after 5-7 years.
The only up-front fees you pay are for the 1031, the sponsor or Leslie doesn't charge you anything.
Frankly there are only a few companies (sponsors) that I feel comfortable with, basically stick with the ones Leslie recommends. In learning about the industry and who has survived and thrived through the down times, I came to care a lot about LTV and debt service coverage ratios in addition to quality sub-market analysis. Leslie helped me every step of the way but doing your own due diligence on not just the deal but also the company is an important part of the process.
Happy to help answer any other questions.