I think Canonical makes a great base for other Linux distributions, but I don't think their flagship product, Ubuntu, is anywhere near as good as it used to be.
For one thing, they seem to do the exact opposite of what everyone else is doing with the Linux desktop and go out of their way to make Unity as uncustomizable as possible. You can't even use any of the tweak tools to put the window buttons back on the right side anymore, they're now permanently attached to the left side. Why? Beats me. I don't know why Canonical seems to want to force that on their users, many of whom come from Windows and other Linux distributions where the buttons are on the right. Also, you can't customize Unity much at all, as opposed to Gnome-Shell, where you can pretty much customize it any way you want it now through various Shell extensions. With a few tweaks, you can have Shell looking and acting almost like Gnome 2, but with the power of Gnome 3 underneath. With Unity, you're pretty much stuck with that fugly tablet interface that looks like a giant turd on a big monitor.
Another thing is, I always seem to run into issues running Ubuntu. With 14.04, it was an issue with my screen freezing, apparently some kind of problem with their desktop or that version of Gnome (because Mint did it too) and Nvidia graphics. However, I've had a lot of other issues with them in the past, since they switched to Unity. For that matter, I always have issues with Kubuntu as well, it runs nowhere near as smoothly as other KDE distributions. The only one of their "official" flavors I'll even touch is Xubuntu.
The Ubuntu forums? Heh. That's where the (partial) misconception that Linux users are a bunch of a-hole neckbeards comes from. There and a few other forums I won't mention. I don't know if they still allow it, but they used to tolerate "code bombing" new users. This is a tactic where, in order to attempt to show their own superior knowledge and make new users feel stupid, childish people will, instead of giving a clear answer to a problem, dump a bunch of code into a reply that makes absolutely no sense to someone trying to learn Linux. Why did they ever allow this? Beats me. But, that's what has made their forum a volatile place in the past. It's also what sends new users back to Windows with the thought that Linux isn't any good because you can't get help with problems. I have no idea if they've cleaned any of that up. And, their forum's not organized very well, in my opinion.
Having said all of that, Ubuntu is still a great project and Canonical is a good company because of all of the great things that have come from Ubuntu. Like Peppermint and Mint, two of the best Linux distributions, in my opinion. I've used some other good Ubuntu derivatives in the past, such as WattOS and Zorin. Those are a couple of good Ubuntu-based distros. Another thing Canonical/Ubuntu has done for Linux is make it more user friendly. Before the arrival of Ubuntu, Debian was the most beginner friendly distribution. As someone who has tried Debian and found it to be not beginner (or user) friendly, I thank Mark Shuttleworth and the people at Canonical who made Ubuntu for improving on Debian's user friendliness. So, I thank Shuttleworth/Canonical/Ubuntu for all that they've done for Linux and all that they continue to do, such as make a great base that people like Team Peppermint can use to make a better distribution. But, I don't consider them to be the "Leading OS" for anything, which is why I always find that dubious claim on their website laughable. Besides, everyone knows the most popular and most widely used Linux-based OS in the world is Android. They're certainly leading the tablet and phone race, even outselling Apple, which makes Ubuntu's claim even more strange. They have to know Ubuntu isn't anywhere near a leader or even a contender in the tablet/phone market.
