I started with Debian and moved to Ubuntu some years ago. I preferred GNOME, because it was most like what I was used to with Windows and Debian. I now use Kubuntu 11.10 after playing with multiple other distros in an effort to escape Unity and GNOME 3.
No specific DE or interface style is inherently superior to another, as people's tastes, usage patterns and hardware vary greatly. That being said, there is a reason I suspect many people will be more productive and happier using a DE other than GNOME 3 or Ubuntu's Unity. Both environments are one size fits all. Customization options are almost non-existent. Whether it's main menus, window management, themes, panel sizing and positioning, panel applets, desktop management or what have you, it's just not there. Want a floating panel? Tough shit. Symlinks on the desktop? Too damn bad. Have a triple-head setup that's no longer effective? Just disconnect two of the monitors and you'll be fine.
Something I noticed about Kubuntu (and KDE in general obviously) is that it is INSANELY customizable. Incredibly I was able to set it up on my dual-head system to work exactly like GNOME 2.x. The only exceptions are that it looks absolutely beautiful and the depth and quality of its core tools are markedly superior.
I don't think Unity versus GNOME 3 versus GNOME 2.x is a valid argument. It's about how much room each offers to tailor the experience to your liking without having to take a hatchet to your system (Ubuntu is supposed to be easy, right?). Here's my setup:
http://www.eightvirtues.com/misc/Kubuntu%2011.10.jpg