How often do you buy new nibs?
my first nibs (I got fabout five with my tablet) went off in few months, then the surface become smooth and now I have nib for more than six months and it doesn't show any defect
is there a large difference between small and medium size bamboo
If you get used to the smaller one, you probably wont miss the bigger... though I hated the fast response when I tried the small one (i have A5 at home). It also depends on size of your monitor. Clearly you don't need tablet bigger than your laptop but it hurts if you have small A6 tablet for super big monitor
what models would you recommend me
if you want to go for A6 I would buy Intuos4, if you want bigger A5 (probably better for drawings as I do) I would buy bamboo, its thin and comfortable...
Sadly, I have no experience with A5 intuos4. I have the feeling it is more expensive than bamboo of the same size though.
BTW: Æthelwulf, for that price, I cant imagine better option
all other are for some silly office work or something, I would never draw with it