I had one of Pro Twins seat's which I sold with an HCRactech GP unit. It is good for the track, it raises you about 11 or 12 mm and you do notice the difference. I tended, as I say, to keep mine attached to the whole seat unit so I could switch it over in about 10 mins. For normal road use I normaly kept to the standard seat as I found the raised one put more pressure on the wrists. Only my experiences ofcourse, it probably also is different depending on your hight and length of back. I am 6'1". kp |