Hummm... if you go to any Product page, you'll see a blue "DOWNLOAD" button at the left in the navigation links up top. It takes you to the "Upgrades" page for that product.
Also, to the right of that button is an "Updates" button that takes you to the same page. There, you'll see all the actively downloadable version links, and below what changes were made to each version change.
As to 5.00, we had some unexpected bugs crop up due to Microsoft changing the way Windows works. They have never done such damage in the past.
We are now on the final release path, and hope to release in April. I'm sorry it has taken so long, but we needed to remove all the problems our Beta Testers reported... some were many years old.