The site notes that while the desktop side of Windows 10 seems fairly solid, the quality of the preview builds has not always been reassuring. For example, there are still some issues with the new app platform and some sites do not work correctly with Edge. Overall it seems Microsoft will be having its hands full to ensure it can deliver a smooth launch on July 29th as having another poorly perceived launch would be terrible for the Windows brand.
Questioned on this matter of Windows 10 readiness, Microsoft executive Joe Belfiore said in April that the core OS was just about done, the shell 85 per cent done, and apps only 65 per cent done.
He also noted that preview builds were "in a rough spot" because Microsoft is still merging work from various teams, implying that it can all come together at the last moment. Recent builds of Windows 10 Mobile have improved dramatically, but until a final or near-final Windows 10 PC build is in our hands, we will not know the extent to which the same may happen there.