MOR23:
new versions of OSX are free.
price is comparable to similarly specced PCs (where you can compare it...no alternative to 5K iMac, equivalent of graphics cards from Mac Pro can't be bought separately etc.).
apps on background stay if there is enough memory, otherwise they're swapped out, so who cares. I think they keep screenshot of last state cached, so it seems more responsive.
and you definitely can use linux on apple hardware.

out of warranty service costs is something I have no experience with, so can't comment on that.

// and no, I don't own any mac, I'm long time linux user...

there are other reasons why I don't like apple hw...no trackpoint on laptops, soldered/glued almost everything in laptops, outdated versions of core unix tools etc...

Customizing a mac: No way, Adding/changing hardware to your mac: No way, Mac OSX has a lot of security issue's because they refuse to update "older" systems in a few years and force you to buy a new version of Mac OSX, have you ever tried to bring your Mac to a place to fix it ? Have you seen the bill afterwards ? There is not much codecs available for Mac, Most opensource apps are there for windows and linux not for mac. Closed apps on MAC OSX tend to stay in background and not close at all which eats your resources. There is no way to re-use your old mac for instance as an Linux comtpuer/server, so you can throw away a machine that is not customizable which you paid too much for :)

Yeah but there is also Steam for Linux, and MAC is not bad it is just overpriced on all sides and you pay for the name, if you compare the price for an average mac and then make a calculation what you can buy if you buy a normal pc, you know you are being anal fucked by a big corporation :)

RAYINER: Especially i use inmac warez forum something similar apps for developers, image editors and so on.

Too late i like my mac!

I'm not OS X user, but I assume that Steam for Mac was the biggest step for gaming on OS X ever.

Anyway, what tools/programs are you looking for in particular?
All I can suggest you right now is Alfred ( http://www.alfredapp.com )

SIRAVECAVEC: Ha! Avoid Mac at all would my opnion say :P

Please share your experience with a MAC OS X. What to avoid, what programs tools, games that made history on mac is welcomed.