@Dennis Perry - you need to factor in lender fees and closing costs. 

I look at Total ROI - factoring in average market appreciation on my cash investment as another way to explain the benefits of investing in real estate. 

Please share your reasoning for investing in single family homes vs apartment buildings.If you are a multi family buy and hold investor and I had a 10 unit single family performing portfolio in Cumberland County, PA what factors would spark your interest?

I'm guessing this doesn't factor in those that have refinanced after closing and bringing this 54% rate down.  

@Jonathan Greene time to dedicate to RE is definitely a factor.

It seems to depend on several factors, age, type (single, double, manufactured), and location.

The articles you are reading on google normally skip a lot of important factors to get to the benefits of a Series LLC. 

If they come in as partners, they can deduct the interest expenses directly against their share of income from partnership.If they come in as lender, they can still deduct the interest as investment interest but might be limited depending on various other factors such as need to itemizing deductions rather than standard deduction. 

Another wrinkle is that I was debating whether it'd be a good idea to get a HELOC on our house as another source of capital, but would that also be factored into my DTI?

It’s never been a factor to me.