We love both resorts and know them well. We own at Shadow Ridge but usually stay at DSV II. Since we are owners at Shadow Ridge we have day use privilege, so when we stay at DSV II we can go there for day when we want! If we didn't have day use privilege we would probably stay there more often. We love the green landscaping of DSV II and the views of Bougainvilla Circle. The shuttle that runs around the property is also a nice perk. If you aren't located close to the main pool you don't have to drive if you are willing to take the shuttle.
If you are talking mainly about pool area though, Shadow Ridge has the best pool area, hands down. Two very large main pools, a pool slide that is actually pretty fast! a great kiddy pool and a small water park area with gadgets squirting water out. The property at SR is beautiful as well, it just a different theme, more of desert landscaping. SR is located close to grocery and restaurants also, so not much competition there. SR is close to Wal-mart and Costco. Read reviews on Tripadvisor also for more details about each property. Look at Palm Desert foru, and search the posts.
Janna