I should mention I did buy my 12 year old a 10.1 last month; we were going to pickup the 8.0 for her, but she got impatient, and she fell in love with the 10.1 when we took a look at BestBuy. I also own a Nexus 7 myself, bought the TF101 for the wife a couple years ago and the 4 year old even has her own Tab 2 7" (we upgraded her from a LeaPad to stop her from stealing my tablet all the time). For the twelve year old, I saw the Note as being great to do research on the web, and jot down notes on the side in a second window. She's also been showing a lot of interest in drawing lately, and it seemed like a natural fit, and so far the hunch is proving right and well worth the money spent.
I don't find that the 10.1 is laggy/slow/choppy at all, particularly after upgrading it to JB, and my playing with it is what made me start thinking of getting the 8.0 for myself, as I really do prefer the smaller form factor. The fact that the 8.0 also has a micro USB instead of a proprietary adapter is a pretty attractive thing too. I just don't know if it's worth the extra cost. I was expecting the Note 8.0 16GB to be more around $375 and 32GB around the $400 mark..
As for it not being a "serious" business device, personally, I don't find any tablet a real "serious" business device. They are media consumption devices that have a number of conveniences, but as for doing serious work on them, the only ones that come close would be Win8 Pro surface machines, and even they can't be considered due to terrible battery life. But in regards to your concerns Mitchellvii, have you taken a look at Amazing note, which is Spen compatible? Never mind..seems to be more of a drawing support... ah well...but I thought there was a note app that did character recognition as well...
Cheers!