Most of the top class smooth pattern flyers fly grasping with finger and thumb. If you had aspirations in that area I would advise you to get a transmitter tray [ at least get a neck strap ] adjust your TX sticks to be as long as possible and go with that option. As an instructor I go with whatever my pupil is most comfortable with.

I learned to fly thumbs a looong time ago and did try the tray and holding the stick but I think that as I am a 3D/combat/pylon flyer I must feel that thumbs gives me the ability to go for more rapid stick movements.