Quit waiting for Samsung to officially release JB for GT-P6210 in US and used link in OP. Download took a little while but actual installation was complete in 15-20 minutes. Everything went smoothly. Three things I noticed about this that I dislike. The Notification bar is now at the top of the screen like on phone unlike my Note 10.1 (also running 4.1.2) where it is on the bottom of the screen. Second is that Return, Home, Recent Apps icons are reversed (mirror image) from ICS - a UK thing? LOL Finally, Screen Shot icon is gone (also like a phone) although I vaguely recollect that there's key combo that will produce a screen shot. Anyway, these are all minor complaints - next step is to root.
I loaded the UK Jelly Bean last month on my 7+ and have been enjoying it for two weeks.
The one problem I had loading Jelly Bean was that the file did not unzip properly (bad checksum) and I had to unzip it again for Odin. Otherwise the upgrade was uneventful. Be sure and back up before starting.
Screen shot is now pressing and holding volume down and power at the same time. I like the new keyboard.
Now that I've had the 7+ for 1.5 years and Samsung seems to have abandoned it, I'm thinking of rooting too. And maybe loading Paranoid Android on XDA developers.
One of my fave accessories is the keyboard dock, which I bought on Ebay for 25 bucks.