I had the RAC replace mine last week, as I had to get them round to 'break in' as the door wouldn't open because the battery was flat.... sorry, I digress.... but when he replaced the old with a new battery, I was surprised that nothing needed to be reset except the date & time on the display between the speedo & tacho.
The alarm that I'd been having problems with, reset itself ok and has worked fine ever since. There, that's jinxed it! :biglaugh:
I have a Pioneer fitted in place of the original Blue&Me unit, and nothing on there needed to be reset except a few preset radio stations.
Maybe worth mentioning - although the replacement RAC battery is the same 600 amp-hour rating as the original, it is physically smaller, including its height. So it could be clamped down properly with the strap, we raised it up by sitting the battery a couple of purpose-made spacers that the RAC man had in his van.