For the fourteen years prior prior to last June I had consistently used some variation of a Dell laptop with Linux - initially RedHat but quickly switching over to SuSE. Occasionally I would dual-boot into Windows to do some gaming, but all of my work and development was done within KDE. I really had no desire to change, even when I was lugging a 12-pound behemoth Precision laptop with openSUSE and Windows 7. Muscle strain aside, I was content with the setup.
The next job I moved to was going to be a switch from my conventional Java development to .NET, so I decided to take the opportunity to change up my workstation as well. I moved away from Wintendo/Linux and moved wholesale into OS X, since my new position delightfully coincided with the release of the latest MacBook Pro’s. Gone was my comfortable NetBeans environment, and instead I had to use VisualStudio within Parallels. No more Linux... and at the time I was confident I would hate OS X and re-build the laptop with KDE 4.
That was eight months ago.
The .NET ecosystem hasn't been fantastic... immersion has not worked in its favor there. The move to OS X has been considerably more pleasant. By and large OS X is still *nix at its heart and ports abound. Even my favorite photo management / digital darkrooom Digikam works within OS X. I haven't really been missing any apps as of yet other than Pidgin. Yeah, there's Adium... but... meh.
The ease of use is much greater as well. The application-based firewall works well, instant messaging integration works (albeit without OTR support), calendaring and mail integration works without issue. By and large things work without any futzing. This is doubly true with the rest of the family; while my attempts to get the household at large on openSUSE + KDE 4 failed miserably, the hand-me-down OS X workstations we've been reusing have been adopted with great enthusiasm. All walks of life have been happy to use 4+ year old iMacs with Snow Leopard, no complaints.
Apple's lustre has been slowly seeping away with the stylish kids of today, but it's hard to deny they've built a solid platform. Yes, it does this by sacrificing your freedom of choice and reducing your hardware upgrade paths. But for now... the walled garden is a damn nice place to just chill out and get some work done.