The risk of poisoning is extremely low. You'd have to eat a huge lot to get poisoned, and the vile taste would quickly stop you from wanting to doing so. Personally, I don't think it a very attractive plant, but that's another matter!
One confirmed death due to Dieffenbachia has been reported. The plant can cause your vocal chords not to work and stings like the "you know what". But poison is a different story. The plant contains an unusual mixture of raphides in the calcium oxalate crystals. I thought you had already read this: http://www.exoticrainforest.com/Calcium oxalate crystals.html Read it now and then tell me what you think about keeping Dieffenbachia.
Far more deaths are attributed to Brugmansia and Datura, than to Dieffenbachia. I vote get it and keep it if you like the way it looks - you'd have to eat huge volumes of it to be poisoned, and as mentioned above the horrific taste would stop you long before you did yourself lasting damage. If you really want to concentrate on toxic plants, I'd suggest being concerned about Oleander and its relatives. They are far more dangerous to you than a Dieff.
I've had them for years, even when my children were young and never had any problems. I did always make sure my cat couldn't reach it as she liked to eat plants but the kids never bothered it and I certainly never got sick!
Thanks for all the great information! Since at the house where i was thinking of growing it in does not have any children or pets in it, i will definatley grow it. Thank you all for your good websites and opinions. I really am thinking about calcium oxide crystals though, because i had a spinach salad for dinner! greenthumb95
Careful! If you believe everything on the net about calcium oxalate crystals you could "end up in the hospital"! It just isn't true!