honda st 70 performance cam

hi guys has anyone fitted one of these camshaft's from shire bikes they claim it improves performance?

http://www.ebay.co.uk/itm/200922690096? ... 1423.l2649

Yeah, it's the ss50 5-speed hot cam.
With a stock limited or retarding ignition: don't buy this!
If you have one with an advancing mechanism, the cam will give you quite a bit more peak power, but it will take away a little of the low-end torque.