A quality local RE Broker/Agent in tandem with a reliable contractors should be able to help you with full analysis of post rehab value.

Hire a Reliable Real Estate Agent (you!)

Hiring a Manager: Decide whether you'll manage the property yourself or hire a property management company.Tenant Screening: Develop a tenant screening process to find reliable renters who meet your criteria.Legal and Tax Considerations:Legal Structure: Consider forming an LLC or another legal entity to protect your personal assets.Tax Implications: Understand tax deductions available for rental properties, including mortgage interest, property taxes, and depreciation.Networking and Education:Real Estate Forums: Participate in forums like this one to learn from experienced investors and ask questions.Local Real Estate Groups: Join local investor meetups or associations to network with professionals in your area.Continued Learning: Attend seminars, webinars, or workshops to stay informed about real estate investing strategies and market updates.Starting with a rental property while keeping your condo as an investment is a great way to begin building wealth through real estate.

Are they ususally reliable?

You could spend some time doing market research and eventually find a niche, an underserved market that was still pretty good with stable/reliable sales, solid comps and investor interest.

It's important to thoroughly vet potential tenants to ensure that they are reliable and will take good care of your property. 

If you're seeking a reliable income stream, checkout Cleveland.

The positive is that the payment is reliable.

Obviously there is a lot to discuss on this topic, but for a very quick glance, here are a few pro's and con's to consider when thinking about section 8 rentals:Pros:Guaranteed Rent Payments -> The government pays a significant portion (if not all) of the rent directly to the landlord, providing a reliable and steady income stream.High Demand -> There is often a high demand for Section 8 housing, reducing the risk of long vacancy periods.Cons:Inspection and Compliance -> The property must pass an initial inspection and comply with health and safety standards set by the local housing authority.

Obviously the answer I'm sure depends on a number of factors (affordability, reliability, etc.)