I don't think the rev hang should be a deal breaker when we were at Berrybrook we drove the A r plus four although it looked gorgeous I thought the engine was very flat even in the upper reaches for a cosworth. We then took out a Roadster and the power was there in every gear.The rev hang was a bit disconserting if your marching on a bit and going into a corner the first time, if you know about it its not so bad. I know for a fact that some people got the upgrade for free and others had to pay which isn't very fair but seems to be the Morgan way