I think that the "stagnation" that has come about in GP's is more to do with the rule book than the use of two strokes. But I have to say that I for one welcome the inclusion of Four strokes and the advances in engine technology and motorcycle design that this will bring. The main reason for the change has not been the fact the racing has become boring or the class has become stagnated but simple because the two stroke engine is seen to be the "dirty" option and not enough of the huge costs involved in development on the track lead to development on the road, where as a direct link can be seen between the development of GP1 four stroke engines and road bikes. Everybody knows that the two stroke engine is by far the most efficent configuration for the production of horsepower but the development costs are lost as far as road bikes are concerned. With regard to the comment that 500 GP is "slow", compared to what ?