Originally Posted by kcmadr
I have recently found that I get good results using ACR, doing my edits, going to CS4, doing further edits as required, and then sharpening and downsampling again.
ACR Seems to do the trick so far, and I already own it so I'll stick with it.

if you have CS4, try this: open image size, enter 375 for the resolution and increase the size (height/width) by 20-30%, select Bicubic Sharper (best for reduction) and click ok. it does a pretty good job at increasing the image size. Bicubic Sharper (best for reduction) may seem like an odd choice, but it works