Derek, there is no doubt that being able to add value, ie develop that property, can accelerate wealth creation. A great number of people do not have the expertise to do that, and can end up spending the profits on consultants. They may also struggle to find funding, when the financier know that the customer lacks the experience/expertise.
In relation to returns, I am a believer/follower of Jan Somers .... internal rate of return .... as the comparison. I do appreciate that it is more difficult to calculate, with our her program or a similar one, however by being able to bring in the tax benefits etc, does assist in comparing one deal against another, particularly in you "tax profile" position. More importantly, it does the calculation on your actual funds invested, not what you have borrowed from others.