Thanks for that!
Yes, mixture, I do know about iDevices and the risks of jailbreaking. However, I don't hack about in the depths of the system: I just run some non-Apple-approved apps that I find extremely useful.
I decided that since the iPad does mostly laptop-type stuff, I'd update it first and see what that did. That was a bit painful: it decided half way through the update to have hiccups and require a "reinstall" which meant all my data and mail settings vanished. No problem ... they were all backed up before I started. Actually, yes, a problem because Apple backup on iPads isn't very complete. It copied all the Apps back to the iPad, but not my settings. "Please enter the password for..." - the password is in a file on the iPad (protected) but it won't let me access that. Memory is a wonderful thing when needed - I found the copy of the passwords file on the desktop.
There didn't seem to be any noticeable difference in the way 6.1 worked (apart from some rubbish maps, as noted), but I sorely missed SBSettings, Infinidock, WiFiFoFum, and a few others. I'm now leaving it to download the necessary: Cydia is (understandably) extremely busy right now.
I don't think I'll bother to update the iPhone. It works just fine and all the Cydia apps function as they should.