At work I've used a MacBook Pro for the past several years, and I'm planning to get another laptop soon for home development use. Is it still the tool of choice, or are the changes towards Mac App Store making it less friendly towards development? Is the extra money worth the value for a serious developer? I'm leaning towards a MBP with 15" matte screen with SSD, but I've heard aftermarket SSDs can be better quality than what Apple provides, but I hear they were Kingston drives in the 2011 MBPs, and Kingston's not terrible, is it? I know Crucial and OCZ make decent ones, too, and Tom's hardware said previously that Intel were the best.
I'm ok using Linux too, but I'd rather spend more time developing and less time messing with driver issues and a crappier user experience like I tend to in Linux. Although, I recently put Lubuntu on a x100e and love it as a fast and modern lightweight OS, though the package manager isn't the easiest to use, but it is much less buggy than the Unity one with the screenshots and icons.
Windows imo is usually not well supported enough for development tools and languages, unless you're using it for .Net/MS development. You end up spending too much time fixing issues that another developer using OS X/*nix didn't test in Windows.
I also really don't like the direction Apple is taking MacOS. Lion chugs resources and does odd things like disable my second monitor when apps go into fullscreen mode. I don't really care much for the direction of the Mac app store, too.
LinuxMint has been great. It's the first time I've really run a Linux desktop since about 2003. What I miss is the polished apps. E.g., Adium is much better than Pidgin and Postbox or Sparrow are much better than Thunderbird. But, overall, I've been pleasantly surprised. Plus, I have 16 GB RAM now (could've gone up to 32 GB) and the OS consumes a lot less of RAM in general.