I know it might well be asking alot, and it's not like anyone here's a TI sales rep or anything, and could probably care less if i buy a new calculator or not, but could anyone with a TI-89 (preferably someone who also has/had a ti-86) write me out a little review of it. what does it do better than 86, what things does it have that the 86 didnt, that sort of thing. thanks.