(NOTE: Being a little pedantic, but the article contains an error. They've been very good to be careful with their wording, but at the start of the second paragraph missed "Spell checking" which should be "Spellchecking". It's an easy error to make as that is one created by their spellchecker.)
Back on topic. That now means spellchecking is only as good as the dictionary you have installed and the standard dictionary contains many issues and errors. I've identified over two and half thousand with Microsoft products. Those using Google Chrome and Firefox will have even more because they use my obsolete open source work.
The best spellchecking experience for Australians is available using my add-in files for Microsoft Office, Internet Explorer and Apple Mac OSX (which covers native applications such as Safari, Apple mail and other applications, but weird as it may sound, is used by Microsoft Outlook). The Mac OSX native dictionary is still a work in progress but even at this stage is very good.
If you're interested in the best spellchecking experience you can find more information at www.Australian-Dictionary.com.au.