Quality and quantity - my experience

I commenced my property investment journey in 2009 basically, and prior to that I was a typical housewife - wanting to pay off home loan and having a debt free life...

Fortunately, my bachelor degree in Economics woke up in time in mid 2009 - after GFC, I knew property price in Sydney was going to hike shortly. Therefore in June 2009 I quickly snapped a house at $890k.  
 Current market valaue should be around $1.5m and I am not goint to sell it at all. 
 weekly rental is $1000 with bills included.

 I moved in this new house after it was settled and I rented out the other house we used to live in (value in 2009 was around $600k).
Then in 2010 I bulit a granny flat at the back yard, which increased the value of the house dramatically. 
Current value of that house is around $1.2m
weekly rental $950, bills not included

 In late 2012, I almost bought a couple of properties in USA - Ohio and Florida. However I didn't like the feeling of 'out of my control' and I held back. 
I knew property price was going to go up again in Sydney. I did some research and found it was so hard to get one close to train station with a back yard for me to build another granny flat. Therefore I adjusted my expectation and in Jan 2013 I secured a four bedroom brick veneer house with 740 sqm land size, price $652k. I did some renovation and rented out at $590/w. In one year I cashed out more than $80k for business purchase...
Current value $850k
weekly rental $590 - property manager suggested increasing rental twice already and I rejected. Good tenant is more important..

In August last year, I purchased a business package including two small properties...current value should be more than $750k...

I have been paying close attention to property investment forums in both Australia and wenxuecity, I find some people can so easily fall in the trap of quantity.  I personally know some people in Sydeny tend to buy a few off-plan properties and feel very good about themselves.. 
For me quality is way more important than quantity in terms of property investment, in particular considering the high dealing costs in Sydney.
So far I have been relying on my instincts...I am still learning, partially from successful people here...:)
 

I shall keep improving...