Your wrong , the 2.03 was done on Sumituno's street tyres not the RA-1. I haven't been to the track yet with the RA-1's but judging by road traction, they are 100% better than the Sumo's.
They are very similiar to the Re55, some guys who have had both reckon they are better, but anyway im not complaining at all, traction is simply brilliant. Guns running big horsepower should certainly look at their tyres to get some rubber down on the street.