I grew one 18mths ago from seed. I overwintered it in the greenhouse 07/08. It was about a foot tall then. Last year I planted it at the side of my garage and it made 8ft tall. Left the stems up the side of the garage in over winter 08/09 and they are now just starting to break bud. I think this year it might go bonkers or I hope so and cover the garage.
Trouble is, you need two, a male and female to produce fruit and they can take about 7yrs to do that ( I can wait though). I have just put some more seed in and any resulting plants will go round the garage too and hopefully I will get a male and female. I find the kiwi plant quite attractive, The leaves are large and have red veins in them. Definitely worth growing from seed.