Yeah, it's not quite that simple unfortunately but in very broad terms, a ceramic magnet will generally give you a tone that is more modern and tighter. I find that an AV magnet is usually a bit more 'classic' and while not quite as tight as ceramic, it ultimately produces a superior tone. Unfortunately, as Lucas points out, there are exceptions so the Miracle Man is surprisingly smooth and organic for a ceramic magnet while the A-Bomb is incredibly tight and aggressive.
The other factor I'd consider is the wire used as I find that this makes a massive difference to the tone. In my experience (others may disagree), 42AWG produces a rounder tone that is softer in the bottom end and is the quintessential PAF tone while 43AWG tends to have a more aggressive and hairy quality to it and gives a tighter bottom end. It retains something of a 'classic' feel but is distinctly more modern than that produced by 42AWG. You'll find that on the hotter and more modern pickups the wire will be either 44AWG or 45AWG as you need to have a thinner wire to fit the extra turns onto the bobbins. These wires tend to lose the 'hair' you get with 43AWG and are tighter and more modern in the tone they produce.
What you end up with becomes personal preference based on experience and that means that while I used to ask for masses of advice when it comes to choosing pickups, now I don't bother because I already know what will work for me. I know I probably won't like a pickup with a ceramic magnet as much as an AV magnet. I did like the Miracle Man and I also liked the Cold Sweat but the Miracle Man didn't quite have the 'hair' I was after so I replaced it with something that uses 43AWG instead and has a combination of AV and AVIII magnets. The Cold Sweat was just a bit too sterile so I had a pickup made for me that was a similar DC resistance with 43AWG but an AV magnet. I loved the Holydiver but the 44AWG wire meant it was just a bit too modern for the 80's Metal tone I was after so I went for one with a slightly lighter wind and 43AWG wire. It's the same story with neck pickups. I know I like AII, AIV or AV and I know that I'm not keen on 42AWG. The best one I've had so far is one I asked to be made for me that was AII with 42.5AWG. I've spent a fortune over the years on different pickups, working out what does and doesn't work for me but it's a worthwhile experience because now I'm in a position where a lot of the guesswork has gone. Without ever having played one, I can say with some certainty that I will like the Abraxas and the Black Dog and I won't like the Painkiller or Aftermath. That doesn't mean I will get it right all the time by any means but that's part of the fun and the learning process. Based on what I've just said I should like the A-Bomb but I don't. I will also sometimes take chances with something just to see what it's like. I've just had a P90 made for me that is the same size as a standard singlecoil for a Strat. Will it work? I have no idea at all but it's going to be fun finding out
