The only reason I want to try out Solaris 10 is dtrace. I have already worked on UltraSPARC machines running solaris, and I believe the x86 version should be no different. (Like Linux, most of the Solaris operating system has been designed to be portable; luckily for the engineers at Sun, only very necessary sections are architecture-specific.)
The install is intuitive; it co-exists with Linux (so I hear) -- you need 12GB of free space. Except maybe the grub part. In any case, a simple installation guide is very much there on their site, but it won't deal with the coexistence I guess. If you need it, I can mail you a copy of the pdf, or I could put it on Hrishi's site.
Regarding the Solaris/Linux comparison pdf, I personally think it is an excellent discussion. However, I have one thing to say -- security is more in the hands of the system administrator, and less in those of the OS developer. And Solaris is extremely difficult to manage well! So, despite the fact that Solaris offers more security than Linux, I would currently recommend Linux to most lesser-than-FBI applications. A much more relevant white paper would have some sort of a metrics to compare ease of administration.
Anyway, fingers crossed till Linux gets its own dtrace :-)