Can see by the post that you guys in England have a few issues with the standard of your dealers ??
Here in Oz I took my car in for a software update. Like some of you have said seems to definitely made an improvement with the lag but sometimes a little delay does creep in. Dont ask me what version of software it was upgraded to. But will be going into the dealer early next week and will ask. I also had to give them the car for a couple of days.