The biggest upgrade was probably Wersi OAS introduced in 2000, as apart from Bohm (Via Hardware) no other manufacture has allowed continuous updates/upgrades to be added to their instruments without forcing the user to buy a new keyboard just to get the few new features and sounds.
Bill
Spot on Bill and that's why Yamaha are still selling KBs faster than any other manufacturer, they have a forward thinking produce development policy, not one like a spluttering tap and they will be around tomorrow and the day after. Not so certain you will agree with me wholeheartedly or even at all. BTW we will take your word for the OAS upgrade, wouldn't mind hearing you play it on the Abacus so we can all judge how good it is, it does biggest not the best!!!