Whatever you may think about Macs and OS X, Apple hardware is very nice. Take the 5 year-old iMac (2008 model) with 24″ LED screen – a bit slow now for Mountain Lion but nevertheless the screen is vibrant, all the hardware is in one box with a 2.8ghz dual core CPU, camera, speakers, DVD, 256mb Radeon video card, 6gb of RAM, lots of ports (USB and Firewre 800) and all. I picked one up for a song with a view of turning it into my new Linux workstation. For a start I had a need for speed so decided to replace the existing old and slow hard drive with a fast SSD. Total cost $150 for the iMac and $179 for the SSD. For that price you would be hard-pressed to get just a screen like that.
Contrary to what you sometimes hear about closed systems and the difficulty of upgrading, I can report that such things are rather exaggerated. There are excellent videos online showing you how to upgrade and as long as you have a range of torx drivers it is easy. The only unusual tool is the need for a suction cup or two (cost $7 for a pair) to remove the glass in front of the LED panel. Good guides can be found here:
http://www.ifixit.com/Device/iMac_Intel
and
http://eshop.macsales.com/installvideos/
The upgrade went smoothly, taking only about 45 minutes from start to finish. The old hard drive came out and the new 240gb SSD slotted in without drama, plugs being the same. Having worked on a few laptops in my time I can report that the iMac was easier partly because everything is a bit bigger and it is not as cramped inside as a laptop. Being an older system, there was some dust inside so I spent a bit of time blowing that out before re-assembly.
Now, set up with new hardware in went the Ubuntu 13.04 DVD. Make sure you get the Mac specific one – I used the ubuntu-13.04-desktop-amd64+mac.iso. Install was completely standard – answer the usual prompts and the Ubuntu install raced away with the SSD coming to the fore.
A reboot had an almost instant appearance of the Ubuntu login screen. Having heard horror stories about hardware incompatibilities I was somewhat wary, but without need. Believe it or not, everything worked out of the box – network, camera and sound all came up without any work on my part. I did use ethernet initially, but a quick install of the proprietary Broadcom drivers had wifi up as well. Also, in spite of what you read, no need for reFit, Bootcamp or other magic stuff, just standard Grub as per the normal Ubuntu install. I had no intention of sharing with OS X or Windows – Linux only for me!
Now I have a speedy Ubuntu workstation with a great screen and a stable software platform. Even sleep/wake works fine – hint: when waking you may need to touch the power button to wake it rather than the keyboard – no idea why, but wake it does work every time without fail. Hardware monitor also works and I can keep an eye on fans, CPU, Radeon and SSD temps.
Update: Today I decided to do the upgrade to 13.10. Again, smooth as – no dramas and I am now running with the latest. All was done over wifi and connectivity was not lost. Again, all hardware was working without any fiddling on my part.
What do I use this system for? As a research student I have lots of references to manage – being paperless all are in PDF or RTF – 1000+ documents at last count. I use Mendeley to manage all these and for fast searching I use Recoll. This is an excellent indexing engine for documents allowing all sorts of complex full-text searches even of PDFs and with the SSD speed is impressive. The SSD certainly gets a hammering, but never a hassle.
I also use Virtualbox to try out various other distros and test various system configurations before rolling out servers and again the SSD has transformed performance. These older computers are not CPU bound but rather i/o bound mostly for what I need and the SSD really is worth it.
Managing lots of RAW photos (from a Canon 5D Mk II) is also a core use of the system and once again all processing is handled smoothly with RAW Therapee, Gimp and such like.
So, if you are looking for cheap, quality hardware have a look at old iMac systems for your next Linux box.