I have a D1 right now and find it very laggy and slow ever since the upgrade to 2.2 Froyo. I never rooted the phone and really never even wanted to. I am thinking about updating to the Thunderbolt this weekend BUT I want to make sure that I won't lose any of the features that I have with my Motorola phone. I am not sure if all the features are the same on the D1 and the TB since they are both using Android. I def don't want to lose things like Voice dialing, Google maps and many of the apps that I am currently using on my D1.