Me, me, please sir, me!
I used to leave 2-3 years between upgrades of my 'proper' workstation. Every time I wanted to upgrade, there was a new CPU socket, GPU connector and a different type of RAM. So, every time I wanted to upgrade, it was: New motherboard, graphics card, RAM and CPU. Every 2-3 years.
This became somewhat tiresome, so I put off my last upgrade a little bit longer and instead purchased a Dell M1730, almost on day of release. As desktop replacement laptops go, it's an enormous (and enormously heavy) beast. Portability and looks completely suck, but performance is drop-dead gorgeous. I don't take it out of the house more than twice a year, but it does make the trip between upstairs office, bedroom and front-room quite often. Not something I'd like to do with tower workstation. It's also now more than 3 years old and I'm only just now feeling the need for an upgrade.
The Acer reviewed here doesn't look particularly attractive as an upgrade option for me, but it's not a bad price for what it is.