I understand that it will differ in each market, but I am trying to get a consensus on where my concentration should be.

I concentrate in C grade neighborhoods in Pasco County.

I will typically use NPV when trying to decide between multiple investment opportunities; I will use IRR when trying to determine if a particular investment will surpass a hurdle (a discount rate).Multi-family syndicators have concentrated on IRR for some reason, and because it's the most common way to measure returns on these deals, all syndicators have to focus on this number in order to provide investors an apples-to-apples comparison of the investments.That said, IRR isn't always apples-to-apples -- like @Thomas Greer said above, IRR make the assumption that cash flow will be reinvested at the same IRR, which is rarely accomplished. 

I will concentrate on growing the business, the portfolio of investments and such. 

Of course I could be completely wrong on that - but I would probably concentrate on finding the first deal, making sure it cash flows, and then keep learning and thinking about what's next and how you'll structure future deals. 

I am concentrating on rentals mostly.

That weeds out 99.9% of the listings, and then I can concentrate my research on a very small percentage of leads.

Right now I am concentrating on Indianapolis.

Imagine where you would be now, should you have postponed the ''fight back'' to a later date and you and your partners would have simply concentrated on making Marco's system work for you?

I concentrate my endeavors in markets where land can be purchased inexpensively, allowing a variety of strategies.