If you plan to start competing, then you may want to make the switch as it does give more control for the majority of flyers who try it, altough there are those out there who can fly just fine with thumbs.

This is really just another user preference.

If you do decide to make the switch, then I would recommend a neck strap. Since more of your hand will be on top of the radio now, it should help give that extra feeling of security that you are not going to drop the radio.