DSCR! There's plenty of lenders out there so I'll leave that part t you. But, as a primer ... No DTI requirement. No Income Verification, No Employment Requirements - these are for creditworthy borrowers who are self-employed, have lots of assets but limited income or even people with a lot of debt in their name (think full-time RE people).
By barring those initial otherwise qualifying measurements - the cash flows of the property become a primary determinant for qualification. They are generally 30 Yr Loans (Fixed, IO, ARM, etc.) and using an LLC is ok.
Like I mentioned, credit must be checked but can be as low as 640 in most cases. Possibly even lower. Seasoning requirement is at least 90 days. For max cash out without restrictions / conditions - 180 days.
The main drawbacks would be marginally higher rates (50-75 bps higher), always some kind of prepayment penalty, and because the asset is the primary function of the loan - a non-cash flowing property (maybe lux or bad market) may not qualify.
Be careful who you trust in the space and place the most stock in synergy and communication (not rates or 'fast closing.')