We raced Kart Mini karts several years ago and were satisfied with the chassis. My concern would be price and availability of replacement parts. Spindles, steering shafts, tie rods etc were way overpriced but if I remember correctly OTK components were close to being a direct replacement.
As far as I know there is no longer a distributor or dealers for them in the US.
There are better chassis on the market now. With a good driver and proper setup you could compete on the local level. If you want to be up front or run nationals you should go another direction.