Hey Steve,
Yup! 2008 vintage is the one, oops, two I've got. Neither one is having any screen issues, but with WC running at full bore that could change. I have noticed a little screen burn in from the same charts being displayed all the time, but it was only visible when the screen was all white. Still, I changed my screensaver parameters to 15 minutes instead of 2 hours and gave it a 5 minute screensaver after that, where before I was sleeping the monitor. It is my understanding that LCDs wont have permanent burn in if you give it active time with alternate screen images.
I took your suggestion and downloaded smcFanControl. Nice program! Well thought out and highly useful in this environment. I put it on both computers and discovered that, with the current WC setup, both computers are running at around the same temperature and minimum fan speeds most of the time. Despite that, I did bump the HDD minimum for the WC computer from 1200 to 1500.
Apple's SSD is currently 256 GB for $600 more. They are due to refresh the iMac product line any day now. It's quite likely that will include the availability of the 512 GB SSD, but possibly at a higher price. I did a quick check of the WC iMac and found that I was still using less than 100 GB, even though there were lots of legacy programs and files that will disappear in a complete HD refresh.
Does WC allow the older data files to be moved to a data drive? If it does, then 256 GB for the boot volume is more than adequate.
I've got one 2 TB Firewire 800 drive that I got lucky and bought before the Taiwan floods. $140 with free shipping. I'm using it as my Time Machine on the main iMac. The WC iMac has a 500 GB standard Firewire drive for Time Machine. I need to upgrade that as well. It's getting a little long in the tooth.