I noticed a difference in the sharpness of my layouts when I last updated my computer as well. It can be a little tricky to get it just right, and sometimes I think my layouts still need a little tweaking. I'm glad to hear that you think they look good.
I think Jacinda and I do almost the same thing for sharpening. I talked a bit about it in my Scrap Like a SugarBabe post on the tutorial blog. It's kind of a long post, but the part about sharpening and saving for Web is about 2/3 of the way down. I also included a download of an action I've created for that process. I don't know if it will work for everyone (I'm on a Mac and using CS 6). But, the download link is at the bottom of the post if you want to try it.
Here's a link to the tutorial:
https://www.sweetshoppedesigns.com/t...-lydia-tarbox/