For what this pedal is made to do, it does an excellent job. Completely transparent clean boost. My setup is Am strat->Marshall DSL100 with the Boosta grande in the effects loop. I bought this pedal to give me the volume boost i needed to switch from rhythm levels to lead levels, but without altering my tone. It achieves this easily. It has heaps of boost to spare, i leave the knob at about 12 o'clock, and that is plenty for me.
I should add that when using this pedal with your amps distortion channel, it should be used in the effects loop. If you use it in front of your amp, you will simply saturate your distortion more, will little to no volume increase.
My only gripe with the pedal (hence the 9) is that when switching it on there is a noticeable "pop", which of course during a gig is no prob as this noise is drowned out by the rest of the band, but at home by yourself it can be a little annoying.
I have gigged and rehearsed with it for around 3 months now and it hasn't missed a beat. I suppose time will tell, but i cant see it breaking any time soon. Don't use a backup cos i not made of money. I give it an 8 because i do not like the look of the plastic battery cover, it could be broken easily. This is not an issue for me as i use a DC brick to power my pedals, but it may be a concern to others.
This pedal is useful for any style of music where you need a volume boost to play leads. I play in an experimental/rock/funky sorta original band, and it serves me very well. For the money (very well priced I think) this is an awesome pedal, which does just what the box says it will do. If it were stolen, i would not hesitate to buy it again.