I just got my 3500 back from being upgraded today. I wanted to post some pictures and provide some info:
Here is the mowing height pre-upgrade at 2.6 inches without the blade guard (way too short of a cut!):

Here is the mowing height after the upgrade at approx 3.25 inches without the blade guard:

Here is a photo of the back of the mower:
(the rock in the background is my cover for my charging base)

Here is a photo from the front:
the upgraded plastic cover has a rubber bumper on the front of it.

When I sent my mower in for upgrade, they asked that I send the charging base for upgrading also. I didn’t send it because I didn’t have the larger box for it. I had Vishal send me the parts. It was easy to do elevate the charging base for the higher / taller mower. I didn’t switch out the wire, because my current wire is buried underground and goes through the wall and into my garage where the power supply, so switching it out would be a big job.
If anyone has any questions / comments, please let me know. I’m not going to mow tonight because it rained here today. Maybe tomorrow night.
someguy