Thanks for sharing! We live in the suburbs just south of Denver and Keystone is by far our very favorite resort to visit. (for all the reasons you mentioned). They are so family friendly. Over the years we've stayed in different areas there-Lakeside, the Forests, but never River Run. Forest is probably our favorite as it is a little off the beaten path, but you cannot go wrong.
For anyone else planning to visit, another great place to eat is the Arapahoe Cafe in Dillon - it is right near the Dam Brewery which we love as well. Arapahoe Cafe does not look like much from the outside but it is a classic.
Thanks for rekindling our memories-especially of the fourth of July when we took DS and DD (now 26 and 21) to Loveland Pass to make snowballs. It was great fun to remember those days!