OK, battery life confirmation: Using my tablet "normally", with no more charging after initial top-up (which completed shortly before my OP above), it's down to 10 hours standby. So, I'm guessing, it would make it a total of 12 hours, if I weren't putting it on the charger now. That includes pretty much continuous decoding (MAD, on the ARM) of 256 ~ 320 kb/s mp3s, output mainly through speakers (~2/3 volume), but some with earbuds (~1/4 volume), and a little HSP, as well as intermittent mapping (MM, BT GPS) and internet (BT DUN and WiFi).

That's at least twice what I'd expect normally, so the battery seems to be doing its job.

EDIT: Turns out I was running with the performance governor, so that was 400 MHz for 12 hours.