SirSlayer, first, allow me to add my thanks for a great thread and the service you are doing to an evergrowing community of users with little to no experience on Android. Much appreciated!
Now, regarding Handcent, do you notice if it has any negative effects towards battery life. I had read that earlier versions of the stock app did in fact negatively effect battery life, so I'm just curious. And once the defaults are cleared from the stock and Handcent made the default app, does it solely receive the notifications then? I used to use a BlackBerry and tried an SMS client that allowed true chat style messaging, but the problem was the stock app still received all notifications too, so you had to clear both programs. That wasn't very practical to me.