My 2350 LMT finally arrived today...

First thing you should do is back up all the files in it's virgin state to your computer.
Make sure to unhide hidden files in Windows Explorer.

In Xp to do so, within Windows Explorer,
it's in Tools\Folder Options\View
Check "show hidden files and folders"
UNCHECK "Hide protected operating system files"

Should be similar in Vista or Windows 7 but I'm not sure.

Once this is done it will recognize all the files on the Nuvi so a complete backup can be done.

When you download new maps the old ones will be removed and replaced, otherwise there would not be enough room in internal memory.
Whenever updating, it's wise to always have battery at full strength since when rebooting a weak battery may interrupt the boot cycle and corrupt your files.
THAT'S THE IMPORTANCE OF HAVING A BACKUP.

thanks, read previous posts and think I did a complete back up. On win7 made sure the box for making sure all files and folders is highlighted before copying the gps to my folder. Can probably burn this to DVD for storage. Guess I did it right LOL.

I assume the battery on the unit charges when plugged into the USB so I don't foresee any issues hopefully.

Download is just finishing now...odd how some it takes hours to update this was a breeze..download is complete and verified but something happened and looks like it is installing again! sheesh..was drawing maps then went to the updater again hope nothing corrupts

The battery will charge when plugged in, so no issues there. You are downloading the maps on an off-peak time, it should go fast. You will see how slow it can be when the next one is released

Yes agreed it charges when plugged in, but this is a new unit and may not be fully charged and will require battery power to boot after the unit is updated. Fully charging the battery is just a safety precaution I like to follow to avoid issues.
Some may feel it's overkill, it's just something I got into the habit of doing.

Pesonally I keep two backups, the original in it's untouched state when I received the unit, and a current one that has all the up to date changes. If something happens and I can revert to my current backup and reinstall any files that may be corrupt or missing. It also backs up all my favorites and POI's. If I modify those I just replace the files in my current backup.

I saw the 2350LMT is on Newegg today for $139.99 delivered and that seems like a lot of features for the money plus lifetime maps and traffic included.

149.99 online at BestBuy Canada, pretty good deal indeed.

Uploading some POI's now, seems easily done so far been years since I have uploaded any.

gotta luv this site!