Hi,
I am an iliad user and a PhD student in Image processing so I read a lot of A4 sized books or papers on iliad, which contain images, tables, numbers and equations. As far as book reading goes it is quite good infact after a while you get so used to reading on iliad that printed books feel awkward and bulky ... but thats my opinion.
To be fair you need to zoom in on the page a little bit to read easily especially if there are tables.
Also if you need to evaluate color coded images or chats & graphs then forget about it .... you will not understand whats going on in those graphs on any of the e-ink devices (believe me I tried)......
So I would suggest that if you have to do a lot of work on color coded charts and graphs then go for a tablet PC (but the eye strain will be there) otherwise if you need to read a lot but look at few images then buy an e-ink device (I would obviously recommend iliad
) and just view the occaional image on the desktop. Atleast thats what I do
Hope this rant helps ....
Asim