I have seen the ToneZone get the "muddy" rap before and I have to ask myself a couple of questions which are:
1. Did the user adjust the height of the pickup
2. Did the user adjust the screws on the pickup
3. and more importantly, did the user re-eq his amp? (ex. turned down the GAIN)
On another pickup forum the Tone Zone gets this very same bad rap only to find out that the person on the other forum had a dual recto, with the gain on full and pushing it with a boss mega distortion pedal. My response to that user was that I could get a 62 strat to sound like mud with those settings. Too many folks believe that the tonal heavens will open and angels will sing by just swapping out pickups and not adjusting the amp and effects (if any).
You know, you hit the nail right on the head with that. Although it's not for everyone, the Tone Zone is definitely a pickup that's requires quite a bit of work to really dial in at times but once you get it to sound good, it sounds great. That's why it's still my #1 goto pickup when I don't know what to stick in a guitar.
Before I respond to this, let me iterate (as I always do before talking about the Tone Zone) that I am a player who likes his pickups BRIGHT. I'm a single coil guy, and strat sounds are where I live.
That being said, the Tone Zone is NOT muddy when readjusted correctly. The two posts above have, as bud said, hit the nail on the head. The Tone Zone is a VERY finicky pickup that you have to get *just* right. But, when you do get it right, you are in tonal bliss.
And I think the Tone Zone, although it may not be for everybody, can work for anybody. I'm living proof. That being said, it's definitely not my go-to pickup (that happens to be the Norton- but that's another post), but it's still great, and I'm definitely trying it out again in the future.