I have the T-handle with serrated blade. I love the combination. It gets you deep quickly and easily and I even use it at my local schools because I can cut a cleaner plug with it than any other digger I have.
I prefer the T handle as it also doubles as a formidable means of self-protection. If you were to swing it the T would stop it from flying out of your hands. Always keep it in handy in your trunk or backseat.