I think that is the theory behind it. 

The ones I have seen also have a lower torque.

David,

Yes, the TX is stiffer with slightly lower torque compared to the X-Stiff.

Thank you

Will

Titleist Will,

In general, what swing speed is needed before someone should look at the TX flex? Will this flex be available at advanced fitting centers?

Thanks,

Will

           
Will,

There are no hard rules when selecting flex. Two people could have close to the same swing speed but if one person has a quicker tempo they might fit better with something stiffer or vice versa. I would say someone needs to be at least around 110 or 115 mph club head speed to be fit in to an X-stiff or a TX flex.

Thanks

Will

According to MRC, 105mph and 260 carry fits their "X" profile. I was fit yesterday and had not issues at 108-111mph handling the X, and in fact I am going to order the TX because of the tighter dispersion. 

Thanks for the info!