Blimey !!!! Good debate, my view is that there realistically was always going to be 2 classes of bike at the DD races, those with 583/674s and those with 620s. The difference is about as minimal as it could reasonably be, its just that with the reality of a big-bore 620 offering, there may in fact now be 3 classes. So my view is; - do away with the big-bore 620 option - acccept that there is a difference between the 583s and 620s - choose your weapon based upon finances and objectives - lets go race!!! FWIW - I paid £2500 for my 620 and all in all have kept the costs below £4K (so far). Not the cheapest or the most expensive bike out there I realise, but a great way to start racing. Tim |