Mustrum_Ridcully
Legend
I use the best of both worlds- DDI access and buying all the books.
Though of course that's mostly the best of both worlds for WotC.
That said, we do not use the DDI tools at the game table, just for preparation. It's useful to have books around - but it's still usually not necessary. I think it's typically most important for rituals, since the character builder usually doesn't print their rules out (I am not sure, there might be a way to do it), and in many cases, it would just be too much. (I think my Level 20 Warlocks has a few dozens rituals....)
Though of course that's mostly the best of both worlds for WotC.

That said, we do not use the DDI tools at the game table, just for preparation. It's useful to have books around - but it's still usually not necessary. I think it's typically most important for rituals, since the character builder usually doesn't print their rules out (I am not sure, there might be a way to do it), and in many cases, it would just be too much. (I think my Level 20 Warlocks has a few dozens rituals....)