The company shows a dyno test claiming to back up the figures quoted and
they look about right, but I don't think they are going to entertain doing a
one off run on my car. Too expensive I would think.

The 'over stressing ' point is exactly what I am worried about, however they
do give you a warranty stating that in the event of any damage caused by the
chip the repair will be paid for by them. Which in itself is a bit worrying!
Not exactly confidence inspiring.

I'm not really bothered about the top end speed gain, more the bigger torque
gain. In the UK we dont really have any roads big enough to max out this
size of car, your either nicked or in hospital!

Thanks for the views guys, think I will leave things as they are.

Cheers.

It would depend on how the increase is achieved. BHP - as you'll
understand but not all will - is a product of torque and engine speed. If
you simply increase the engine speed while maintaining the torque output
you'll get a higher maximum BHP figure which as you say most won't notice.
But if chipping increases the torque across the range by the equivalent of
about 5% as claimed IMHO you would feel the difference. But it's a very
big 'if' with most modern systems. Simply increasing the fuelling can
achieve more power at the expense of economy and emissions sometimes.  

Could be, although most can manage a fast start in a traffic light GP. ;-)