I have an entry level guitar, and following many suggestions online I have decided to use one of the best pick up around. I was looking for an aggressive clear tone, and that's exactly what I have got. I use it for rhythm and solo with distortion sounds, I almost never play clean tones, but anyway in that case the pick up gives a very nice bright fuzzy tone. That is probably not what you are looking for if you want a jazzy crystal clear guitar tone, but in rock or metal is perfect (that's what I play).
For a reasonable price now my guitar sounds like a pro one. The rhythm is not muddy anymore, but sharp and aggressive, exactly as you would like to have for some good metal.
Tips: Looking at some tutorials online, I thought it was pretty easy to install it. To do so you have to unsolder your previous pick up, and sold this one. I have never done something like this before so: if you have some expertise it will take you 10 minutes, it is really a child game. If you do not have, go to your guitar doctor, it will take 30 minutes and not so and you do not screw up anything in your guitar.