However, I've still had some problems with hardware support in a couple cases (each Ubuntu release seems to fix some problems and introduce others)
At this point, Linux hardware problems are not significantly different from Windows hardware problems (e.g. a fresh install of Linux on any given PC is at least as likely to run fine as Windows, probably more likely since more up-to-date drivers are included), but they're harder to fix when they do occur due to lack of direct manufacturer support.
In Windows it's usually "go download the driver from the manufacturer's site", in Linux that's less likely to be an option, and if it is, the installation process is probably going to involve the command line, which scares people.
and you're still missing some commercial packages that might be vital for a lot of users (e.g. Photoshop, where GIMP is pretty good but might still not be a viable alternative).
If you already own such packages, most of them work well in Wine these days (and Wine is a lot easier to use than it was in the past, though still not what it should be).