Hey, I have just bought a supercharged (HKS) Z and also own a Stuart Taylor Aries with Yamaha R1 engine, 495kgs all in with fuel. Going up for sale in the New Year by the way. I have used the kit car mainly for track days at Knockhill for the last 4 years, amazing car, direct, super nimble and a giant killer. The Z feels very quick but not had a chance to really try it out properly yet, will be taking it to Knockhill next year (anyone going next year look for the Azure blue supercharged Z and come over and say Hi) but hope to get a trip to the ring to really try it out. I think it will be more suited to the higher speeds than the twists of Knockhill. Two different animals really and not fair to compare them. Only real issue with the Z is a lot of tramping at the rear which I hope there is a cure for. Looking to sell the kit car to keep the Z long term now, better all round useable car that will still put a smile on your face. I would definately recommend one even after only owning mine for a couple of months and spending half my time offshore not getting to drive it. Plus point for me is the wife loves the Z and hates the kit car and seems to swear a lot and question my parentage when I am scaring her around Knockhill in the kit car.