Yes I have one and initially was very taken by it. However, I've reverted back to using my regular kettle.
Although the Tefal machine does give out hot water instantly, I found it was never as hot as kettle water and it cooled down quite quickly too. If my cup of tea was left standing for 5 minutes, it became lukewarm. Also, I didn't like how the water always had a strange film on the top, like flat froth.
If you want to read reviews on products like the Tefal Quickcup, try going to www.ciao.co.uk.