I'm probably going to regret this but recently I got to do a fresh install of both Windows 7 and Linux Mint 15. I decided to do them side by side to compare them. I did the fresh install of Windows on a Toshiba Satellite laptop for a friend and I installed Linux Mint on my older HP desktop. The only things I was going to add to Windows was Office 2010 and Adobe CS5.
Install times were very similar. The rub came when I started doing updates. In 30 minutes I had not only updated mint but added PPAs to update Libreoffice, Gimp, and VLC to the newest versions. It took me nearly 4 hours to install the updates in Windows.
While Windows was chugging away, I spend another hour in Mint getting some more PPAs added, for themes and for Handbrake and FormatJunkie and the Sunflower File Manager. That took another hour, mainly because I was just taking my time and trying out new themes.
So to summarize, Windows took me me nearly 5 hours to install and update and Linux Mint 15 took me 2 hours.
On the Windows box, I then installed Office and the Creative Suit. To install them and then do the updates took me over 2 hours. I charged my friend for 8 hours of work. I had done been finished with Linux and had posted on many sites and had even ripped a movie and converted it with Handbrake.
So on round 1 (installation) Linux wins easily.