Helps with your debt to income, better opportunities at cash flow, and typically requires less down to purchase.In regards to challenges, I usually build in an extra 10-15% to deal with things that I can't see behind the walls, including dry rot, electrical or plumbing issues, etc.

Quote from @Richa Wardhan: Regular lender financing, we have paid off 70% of our mortgage on the primary residence so we were loaned money without any issue. 

But the answer for everyone may differ.Here are the personal attributes I see in those able to achieve a higher than market ROI, enough higher to be able to “scale”.1- Knowledge of real estate principles, real estate law and real estate finance2- Minimum 3 -5 years full time, or near full time experience directly related to real estate investing3- Ability to utilize technology for increased efficiency, capacity, and accuracy4- Excellent hired legal counsel and excellent hired marketing help5- Established method(s) of obtaining consistently high QUALITY deal flow6- Ability to manage and choose people who are NOT employees: Attorneys, Appraisers, Mortgage Brokers, Real Estate Brokers, Title Companies, Surveyors, Marketing Specialists, Accountants, Contractors, Consultants, Property Managers7- A VERIFIABLE track record of success8- Ability to identify, analyze, and negotiate a deal that can be “worked” for “enhanced” ROI9- Some type of competitive advantage; for example for me it’s my ability to analyze and identify mortgage loans that are actually less risky than all other lenders believe (on the investing in debt side), and on the real property side it’s my ability to analyze”pull the trigger” with LESS information than other investors need,  combined with the ability to pay cash, or raise significant capital almost instantly as well as being able to obtain loans at the lowest prime customer bank rate with no recourse or personal liability.  

If not, then you really need a strong legal structure stating how these properties will be governed going forward, including management, tenant selection, capital expenses, etc.

Clay soils mean that drainage is really important to prevent foundation issues.

Had structural issues (wall caving in) that I addressed a couple years ago.

See the old mom-and-pop investors in their sixties that you are trying to buy off-market properties from.This is like people who buy for cash flow but don't realize that with the best cash flow comes capital expenditures and tenant issues.

A "non-refundable deposit" is legally confusing.If they do request a showing, I send them this email:Hi John,Please read this entire email.How about a viewing on X at X pm?

There's a good chance the issue(s) you face has already been discussed and answered.Ask questions in the appropriate forum.

Gee - Guess that means every amortization schedule ever issued by a lender or anyone else is wrong!