I ask this question because by early 2009 mini is nearing it's 4th year and it is running as smooth as ever. It pretty much does everything I need and I honestly see it being my main Mac for anther couple of years. 6 years of use as my primary Mac would make it a great value.
Not a bad run of far. I upped the RAM to the max (4) when I first purchased it and I'm thinking about an SSD down the road to see if it gives it a bit of a boost.
Similar story; I reckon my early 2009 Mini should be good for my needs for several more years.
I have the base model. It replaced the my original 2005 G4 Mini, on which the HDD and power supply had failed. The early 2009 came with Leopard, which had its shortcomings. I upgraded to Snow Leopard as soon as it came out.
By mid 2012, the 2009 Mini had become quite slow. The 1 GB of RAM was not up to the demands of the software updates that had been installed, and the HPSA mobile based internet connection I got when they discontinued CDMA; there is no telephone line to my apartment.
I put the Mini in to to the shop get the RAM upgraded, and have Mountain Lion installed (no credit card for me here, so no App Store a/c). They added 4 GB, so now it has 1 GB + 4 GB = 5 GB of RAM. I am well pleased with the the resulting performance improvement.
The original HDD still seems fine for now, but when it becomes dicky SSD will be the way to go.