I have some experience with vacant land flipping but I would like to meet and communicate with other investors at Biggerpockets who actively concentrate in vacant land investing, subdividing, and flipping.  

Do you specialize or concentrate in a particular class of property?

http://www.forbes.com/sites/timworstall/2015/08/02/uber-reduces-capital-concentration-and-increases-the-number-of-capitalists/I thought this article was an interesting one and wanted to share.

Considering my hefty goals, investing in this space is where I need to concentrate my attention.

Concentrate on your career, max out your 401k and do a good job to maximize your salary and bonus for the next 10-15 years. 

Are there areas of Florida that I need to concentrate on for buying tax lien certificates?  

I’ve done the same searching except have concentrated in the Palmetto Dunes plantation.

Trump might have wanted to concentrate on Business so he appoints someone that would focus on that.

The map view is most helpful to determine the concentration of competition in your area. 

I think that this is the optimal route in terms of return on time invested and risk reduction via diversification.I do think however that if you are willing to dedicate yourself 100% to being the sponsor then you will make more money, at the expense of time and with more concentrated risk.In summary, being the sponsor is the best option for the few and being a LP investor is likely the best outcome for the many.For full disclosure I run a company that helps LP investors find the best sponsors in a given asset class or geography.