I found an example of extremely poor spellchecking on Google Docs (now part of Drive). I've provided a link to the site where I found the information.
For me what initially caught my attention was the spelling 'wright', which didn't seem right. I checked in Microsoft Word and the spelling was accepted as correct. It is correct, but some online sources consider 'wright' to be obsolete. The authoritative dictionary references for Australia (Macquarie and Oxford) both list the word and whilst 'wright' is generally considered to be used in conjunction with another word, 'wright' isn't flagged as obsolete, so 'wright' is a valid spelling. At this stage I'm not including the spelling 'wright' in the preferred Australian English dicitonary as it would be rarely used and could lead people to use the incorrect spelling. Should I find evidence to the contrary I will add the word 'wright' to the dictionary file.
However the bigger issue was the example the person gave which shows the terrible spellchecking by Google's service. Surely this isn't right. This is the example text which is shown in the link.
thiz iz the rong speling for moste ov thiz dokument befor I kant spel wright speling dokument wann yur.
When I type the words three of the words are correct (I'm using my own preferred Australian English spelling dictionary on a MacBook Air). In Microsoft Word four of the words are spelt correctly. In Google Docs 12 of the words are spelt as correct, which means 8 that should be marked as errors aren't.
If this is correct and applies both to the free and paid versions of Google writing products, then I sincerely apologise to anyone I've suggested to use Google's services. I'm hoping it is a trick because the spellchecker appears to be inadequate and I simply can't believe it. If it is a trick then they've got me and I'll feel a bit of an idiot. I can handle that. But if it isn't a trick and Google's spellchecker is woeful, then I've been making poor suggestions for people to use Google Drive/Docs and for me that isn't good enough. If someone has paid access to Google's document app and could test this for me it would really be appreciated.
Thank you in advance.
PS. It should be noted that it appears that Google is trying to spellcheck the words and if you go slowly enough more words that are incorrect appear to be marked as incorrect. Certainly weird.