If you want to know why this bullet is worth it....take a look at the video I made for my review blog if you like:
I got 5 or 6 bullets, including the Tango, some Rocks off bullets, Tracey Cox bullets, durex bullets etc and show you the strength of the vibrations as they travel through water:
http://grittywoman.co.uk/video-reviews/
(It is the main video, titled "bullet vibration test") It isn't an exact science but this will show you the difference between lots of standard battery operated bullets, and why everyone raves about the Tango....I won't spoil the fun :D. Do I recommend the tango? OH YES YES YES! Enjoy the video!