There a totaly different level, I had a prokart with engine mods and then moved to the Rotax and its like the difference between a 1.2 and 2.0.
The twin engine karts run two 6 hp GX160 4 stroke engines and this is lighter with a 125cc 30 hp 2stroke that revs to 13000 rpm.
The only reason im selling is ive just bought a 40hp 125 gearbox kart.