I use them.
Some complain that they are thina nd do not fill the hand well. So, the finger is not "placed" in the right spot, so you need to think about where your finger is, unless you have fat hands, short fingrer or both. I use gloves almost all of the time, so those take up a lot of slack.
Thin grips over tima can lead to hand fatigue, like the difference between holding a bat a long time and the wrong end of a screw driver. Trying to hold the thin screwdriver firmly will wear you down quicker than the bat, the bat just fills the hand better.
The bite of the std. A2 grip's gone though w/ a duckbill type extension under the trigger guard. I like mine a lot, and have used the A2, the SPR, and the Ergo type. Like them all, like the TD as much. All are different but I don't hate any. If you want to open and try your TD go ahead, if you don't like it, I'll give you your money back for it, there's always a lower in need of a grip around here.
/S2