They let you simulate how your credit score is affected if you make certain changes - close a card, pay down debt, etc.

Cash flow and appreciation.In general, even leveraged cash-flow property can not outperform S&P in total return because their appreciation  for 16 years is so low in term of absolute dollar (due to R&M).While leveraged appreciated market could outperform S&P in many ways, in gross it's similar to be having 15% CD in environment where yield=2% One could simulate this using ZHI.Property that can beat S&P is always always expensive top tier homes price 300K in 2009-2010 and appreciates more than 20% IRR from that time.Once IRR is below 10%, S&P would perform better because its appreciate 7-8% annually ( even better if one absent not to particpate during the bad times).

So run your number and do a lot of simulation.

That's the same simulation that posits if an axe-murder asks you if your family is home because he wants to kill them, you must answer honestly because lying would be immoral.