Big surprise for me: I've upgraded 4 years old laptop with new SSD disk and 12.04beta and its really lightning fast compared to windows 7 (altough I have to switch to Unity 2D because of too hot gpu). It really feels like new machine.
Unity has dynamic search &c and I find it takes a little time to build the Dash home lens.
Because the Gnome Shell 'Activities' overlay is not building a dynamic list, it seems to appear almost instantly.
Anyway I am really suprised by overall performance, apps start very fast and laptop has 4 sec suspend/3 sec wake up. (altough it often takes additional timea for wifi to reconnect again).
The Dash home lens is actually providing a lot of context by listing the recently used apps/modified files/and even the played music. I sometimes wonder how many people use that context!
The times for the app loading and suspend/resume is down to your hardware which is obviously fast with the ssd.
- Installing the proprietary drivers (fglrx). https://help.ubuntu.com/community/BinaryDriverHowto/ATI - Properly configuring power management for the libre ones. http://ubuntuforums.org/showthread.php?t=1569512
Disclaimer: I'm not an ubuntu user (debian here)
However, for Linux to be a 100% replacement for Windows or OS X, we have to use to non-free software for some things. You could always choose not to do those things, as Stallman does, and sometimes I'm tempted given how little real utility movies and whatnot have in my life, but for Linux and all the free software it brings to make headway with the general public, non-free software is a necessary evil.
It's a tradeoff, both sides have pros and cons, gotta know them, and make an informed choice.
If one doesn't want the other using their technologies, make the source public under a non-open license and sue the other if they use it. BTW, offer an easy and automated way to build, test and install the kernel modules.