10 k boost is £20 at Halfords.
I used it and it is basically carb cleaner in a really big can. It does make a difference, especially if you have a coked up system and oil and goo etc. I noticed it straight away.
But I doubt it is any more different than normal carb cleaner that you can get for £6 a can. I've tried both and next time I will just buy 3 cans of STP carb cleaner i reckon.

Also get some injector cleaner (I used STP for £6).
In a nutshell get the fuel system cleaned up first, it's cheap to do and I bet you will notice a big difference in response and power. I did.