relatively (ir)relevant, then ?
Ah, the OS-es.... always good for a laugh and a fight..... Frankly, I did them all, or at least a fair share of them, and got all the t-shirts. (linux,aix, solaris,vms,os2,winnt, a bit of novell and <......>)
I find it very irrelevant which one you favor most. I think the point is, what are you trying to achieve and how much green can you spend ?
For example..... ;-)
I know linux for what it is good at: webservers, maybe some java and currently my AMD X2 desktop. ( multimedia, sound recording, satellite tv-watching, productivity apps, the works). The system mgmt interface on e.g. SuSe is an example of how to do it. A medium / small business might very well run its entire IT on it, and never be sorry about it. It won't run your 6000-session website, though, unless you favour to have 200 servers, 10 admins and the space to put them in...... Linux is there, and it will grow, because it caters a need.
By it's shear market-share and it did force all the unixes to standardize on API interfaces, which is good; today you can run linux-bread software on any unix you ever heard about...... and the other way around.....
Solaris is solid on all kinds of server-tasks. However, I would not dream of having it on my desktop, because I will end up re-compiling linux software to get stuff to work; it does lack menu driven admin interfaces, though. which makes it a costly affair to train people for it... most young kids today aren't interested in typing arcane commands, and some day they will have to take over.......
AIX is solid for all kinds of server-tasks, just like solaris; the big bonus is that you get the fastest hardware on the planet and a day2day system mgmt interface that is easy to learn, without having to know the inner workings of unix.....
On the upside, doing complicated batch processing with a lot of interdependencies is something one doesn't want to do on any unix to begin with..... if you are used to mainframe capabilities.....
RG