No, they are not very large in terms of diameter, but they will get very long. I think it was Steve Stewart who had one that went all the way up to the top of his greenhouse. A ladder was necessary to get to the flower.
I don't think these things get more than 6" or so across tho...definitely no more than 8". Sorry I can't provide you with exact dimensions.
If its the TC clone that everyone has...don't feel bad if you kill it. It's a weak clone and I don't know of anyone who's had it and hasn't killed at least one. Well I didn't kill mine...someone killed it for me when I was on vacation in Germany haha.