I love Nathan Birch and the amount of wealth he has been able to create in such a short space of time.
I think his message is fantastic, it all depends on which part of the investing cycle you are in. The most important thing is that you set yourself a financial goal, whether it is a certain amount of equity or monthly cash flow.
If you are trying to reach a lump sum of equity you need to keep reinvesting your profit back into property and having it grow. Then you have a choice. Lets say you wanted $2m of equity. You can either buy $2m worth of property, hold onto it and then buy and sell other properties and pay down the debt on your hold portfolio. Or you can you build your portfolio until you have about $10m worth of property leveraged at 80%, which would give you $2m of equity.
If you are after cash flow, you can keep adding cash flow positive properties to your portfolio until you have reached your desired cash flow position. As the properties equity grow you can leverage off that to buy more cash flow positive property. Or you can buy properties with a great yield that will pay you the cash flow you require, and then simply pay down the debt on that property until you hold it unencumbered in which case you have no lending costs so you receive the cash flow required.