The cover never changed. In the old days (2004-2006) there was a foam insert that caused a lot of corrosion. I have seen many with corrosion, but none so bad they needed to be replaced for it. Post up a photo of yours.
Once the corrosion is removed, and the cover properly painted, the corrosion will not come back.
As for ease of changing it, do not be fooled by the Haynes manual. It is more difficult than it looks, and getting the new one, damned expensive, back on with the RTV sealed, and the main shaft seal properly installed, is harder than one might think. The space is very tight to get it past the Telelever, and to do it without removing the applied RTV, then getting the seal on right without folding the lip, is no bag of fun.
This is an R1150GS, but it is similar to the R1200 in difficulty.