I have the same unit, and would be curious to hear others' experience with the upgrade. Since I don't have a Simrad
MFD on board, I'd have to un-install it and take it to a shop, and (pay to) have it updated. Not something I'd really like to have to do very often.
One thing I have heard is that the upgrade fixes a bug where the radio
randomly switches from normal VHF
channels to one of the WX channels. I've had that happen a couple of times. Somewhat inconvenient to say the least, but so far not as inconvenient as un-installing and re-installing.