As 'G'raham will testify, the auto box doesn't handle lots of power too well....
Strictly speaking...the box is ok.
The issue here is the actuator and what it does or is required to do.
In standard 'trim' it copes/works admirably, and it gives a smooth
'fluid auto' type change (except going down from 2nd to 1st).
If one were able to 'beef up' the motor (and the gears it uses), in an
attempt to speed it up, or to handle a more powerful clutch, then I
feel that the gearchange would lose the smoothness it currently
has and end up being jerky.
But hey...I'm not an engineer.....this is just my opinion, and my own
experience's I'm quoting from, ok.