I have found my subscription to be useful. I don't necessarily use it for making touring plans, but I like having a subscription with them when I have a trip planned to either WDW or DLR. I like looking at the crowd calendar and using the dashboard to make notes about my "plans" for each day. It also indicates which days are early entry and if there is anything special going on that day and what passes, if any, are blocked.
The cost is very minimal compared to what I'll be spending on my trips, so it's worth it to me to have the additional planning information. Plus I just enjoy it!