As a long-time Doctor Who fan I just couldn't resist getting one of these, and I honestly don't regret it. It looks good, and the UV light and ink is a neat touch. Some people have complained that the sounds are too quiet, but I think they're just about right. The two sounds are subtly different (but very authentic) and you have to listen closely to tell them apart.
What's amazing is that the BBC reportedly have started using these in the new David Tennant series as they are more durable than the real prop! (the toy is about half an inch longer than the real prop as it has to accommodate sounds and batteries).
Also, contrary to the Amazon product description, it appears that the BBC are now supplying these with batteries as standard, and they have also begun re-supplying them in new packaging featuring David Tennant.
If you're a doctor who fan of any age, I would recommend this to you. Well worth the investment of a tenner.