I was quoted about £80 to replace the rear cassette on my bike, I bought this for under a fiver, and removed the cassette easily. I also purchased a chain whip with a new 8 speed cassette all for under £20. So have a go yourself, and save money.
This does exactly what it says it does and is of reasonably high quality. However, I'd like to see a version with an insert for a torque wrench.
I had to buy a 26mm socket to use with it, which surprisingly wasn't that easy as all of my local car parts / DIY stores only stocked 24mm or 27mm. Luckily I ended up finding some in a Swedish hardware chain store with the initials CO.
This is a very good product for those passionate about their bike and are not afraid in taking on repairs that are generally difficult but this little tool will definitely simplify the tasks ahead. Love it!