Doug,unless you actually need a flat bed scanner or money is an issue, I agree with Chris-- go with a dedicated slide scanner. The Nikon Coolscan V, with a street price somewhere in the mid $500s would be an excellent choice. The results will be so much better.
I faced the same dilemma that you have. I have almost 30 years of slides and wanted to go through and digitize a good number of them to archive, make prints, and/or turn into sound slide shows. Even though I had an Epson flatbed that had a transparency attachment that gave usuable results, I decided to go with the Nikon Coolscan V. The results are stunning.
The slides scan at 4000 dpi in about two minutes using the ICE correction and take about another minute to save through USB2. The raw scans are about 120MB in TIFF format. I then open the saved image in Photoshop and size it and change the dpi setting to whatever size I'm planning on using.
Whatever route you plan on going it's going to be a project that takes some time to complete.
Good luck.