From that article:
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Both free suites also support the proprietary but widely copied formats that Microsoft used in its basic Office products until the 2007 version. Although Office 2007 programs can read and write traditional Office formats, their native tongue is a new format that only Microsoft has adopted so far.
For now, the free, open-source suites might have problems with native Office 2007 documents. But I think experienced Microsoft Office 2007 users will save documents in the earlier formats, anyway, just to keep things straight with people who might have to read them with older versions of the program.
That's the key to being a competitor to MS. Avoid the proprietary format when possible. Wish more people would take the time to investigate the options when saving a file.
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I've found it handy at times - it has some neat features and plugins.
I agree that it does, but I had major problems getting fonts to italicize and bold and such; but to be fair -- I was still running an older beta version because I have never been able to get the "finished" product to download.
My other grip - and it became the main turn off point for me -- every stinkin' time I launched NeoOffice it opened my browser, moved it to the forefront and sent me to a "Why not donate" page.
I had donated when I first downloaded the program and was using it on a reg. basis. It irks me to be nagged for more money on a consistent basis.
If they need money that bad, then they should require a shareware fee to make the program work. So, that was the killer point for me.
I paid my bucks for Marine Write, it works and they don't nag me every time I launch the program. 
Your writing mileage likely varies.