Does anyone have experience with such offerings, and would you say whether you think Groundfloor is worth direct investment of this sort?

Good afternoon, Can a self directed IRA hire an organization for services owned by a non disqualified person, who in turns hires a disqualified person? 

It's not directly addressing your question, but I hope you find it helpful.  

Has it been through loopnet, working with an agent, direct mail, or some other method?

Please feel free to shoot me a direct message so that I can better understand it.

The price you pay is directly related to the risk associated.

If you own something directly in a major metro, and it is not too much of a financial pinch to prevent you from steadily adding to the portfolio in a less expensive area, keep it.  

I would probably need to speak with them directly on how to structure this, including creating a company. 

Assuming I have a Roth 401k at etrade, where half my account is tied up in equities, and the other half in cash, can I move the cash portion into a new self-directed 401(k) to use for real estate?

Until he learns the regulations he should not be dealing directly with tenants.You are responsible for learning your state regulations and can usually find them on line.