I have a confession to make.
My main home computer runs Windows XP. Now, I'm a Solaris guy, so you would expect me to have banished Windows, but no, most of the times I use a computer at home it's the Windows box that gets the nod.
There are reasons for this renegade behaviour. The two main ones are Windows ability to do suspend-to-RAM and fast user switching. Essentially, if I just want to check my email quick, then either the Windows machine is on already and I just have to switch user, or I hit the power button. In both cases it's about the time it takes me to get the seat located comfortably before I'm online and working.
Solaris can't match this. If I'm working at home then the Sun box comes on, as the superior behaviour and environment are worth waiting 10 minutes for. The boot time is awful; the JDS startup time is awful; suspend resume is only on sparc and is very much hit and miss. If we're after wider adoption, then this is a huge area we have to address.