I only owned an A1000 and A1200 myself.
So i pick up A1200, which is towered and has some nice hardware atm :-)
I have seen and used a friends A4000T though, can't say i don't like it, but too pricey for poor guys like me :-(
Can't decide if i should choose the A1200 or A4000 now :-)
Well, i guess it will be the A4000 then :-D