Maybe initially you are at break even on cash flow but after a couple of years your property will have appreciated and rents will most likely go up.

I can tell you right now that you're not going to cash flow $6000 a month on a $500K cash purchase anywhere close to NYC (or maybe anywhere, I mean, that's a 14.4% cap rate).

After I move, my brother and his friend would rent the space out for a place to work during the day providing me with a potential 300 - 500 in monthly cash flow assuming a 30% expense rate.

Basically, you need it to have a tenant and cash flowing for a few months before refinance.

Heard lot about awesome cash flows but haven't seen much discussion at BP.

Each quadraplex would cash flow about 500/month for a total with all 16 units at 2k/month.

You need to look at cash flow, rental desirability, etc. 

This method won't increase my monthly cash flow much in immediate future, but as loans are paid down and hopefully appreciation occurs, my overall situation should improve dramatically. 

We plan on having 4 units cash flowing and once paid off in 5 yrs we will use property equity to complete the remaining unit.

It has worked for us in the past and that fascination of homes we explored while looking for a deal in my youth, and the different factors that led to a wise purchase  has strongly flowed over into my current life.