The Simply Everything represents a good all around value, and with Any Mobile, Any Time, you'll now have the ability to call anyone else's mobile phone without taking away from your anytime bucket. Unlike AT&T Wireless and Verizon, you can start your Any Mobile Any Time Plan with the 450 minute plan, instead of going with their second tiered plan with 900 minutes.
If you're currently a Sprint customer on an unlimited plan, or anything higher than the 450 minute plan, take a moment to go over your bill and highlight any phone that is a mobile phone number and consider lowering your price plan.
Just keep in mind, as with any carrier specific features, they only work on their home network. If you roam alot, or live in a crowded city with many cell towers, it might be a good idea to turn roaming off to make sure you're using your carrier's mobile to mobile (or in this case, Any Mobile, Any Time) calling features. This is especially important with this product, as the numbers you're calling aren't pre assigned, as with Fave Fives, A-List, or Friends and Family.