I'm with ANSA on this one. The reason for an intermediate level requirement or restriction doesn't vapourise into thin air just because a pilot decides that his/her aircraft can go another 2000FT higher than the current, cleared level.
If the pilot requests, and is cleared for additional climb, logic would suggest that this has in no way changed the situation that required the intermediate level requirement/restriction.
Controllers are conservative by nature and will defend the Status Quo in the face of logic and reason to the contrary, but surely people can see the danger in allowing this one to continue?
250 kts, keep on this one.