For those who don’t know what Google Keyword Tool or Wordtracker is, they are keyword research tool which shows an approximate value of the Search Volume of a Keyword and its competition.
Ever since Adwords introduced its modified Keyword Tool, it became a serious threat for Wordtracker. Wordtracker was the tool every webmaster or Domainer were using to research for Keywords before investing on a site or domain.
The Google Adwords Keyword Tool is free whereas the Wordtracker remains paid and this is not the only difference. If you look at the screenshots, you can easily guess why the Google Adwords Keyword Tool became popular among the researchers in a short period of time. It gives detailed output and some extra stats which Wordtracker don’t even in paid mode (Reported by a paid user).

Check the Google Keyword Tool ScreenShot:

Google Adwords Keywords Tool
You can see that the output results are very prominent and well managed. The Related Keyword suggestions are also good. Now check the ScreenShot taken from the Free version of the wordtracker. I haven’t used the Paid Version of this tool, but all I can say that its worthless in Free Mode.

Wordtracker ScreenShot:

Wordtracker Keyword Tool