I've bought the same antenna, and I've got worse results than my home made Cantenna... 
When I purchased Flightaware antenna,  it worked worst than my Cantenna. I finally discovered that this was due to strong RF noise (TV, FM, Cell/Mobile signals). The RF noise is very high in my area as I live in an urban high rise buildings area.
Adding a filter to Flightaware antenna grately improved it's performance,  and it started performing much better than Cantenna. 
To check RF noise in your area, please see following How-to, particularly 
OPTION-1 and 
OPTION-4Do I Need A Filter? .
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