I put neo magnets under my SX 6er pickups to increase the output and I REALLY like what it did. First off it much increased the output without increasing the hum in these single coil pickups. Note that many pickups increase output by overwinding which also increases hum (more turns) and changes the tone (Increased inductance). Adding magnets does neither of these things.
My big worry was the story that stronger magentics will attract the strings and kill sustain. Well, I noticed no string attraction and furthermore, it seemed to me that the sustain was actually MORE than it was before, though I can't explain that! Perhaps it was that the stronger magnets just allowed you to keep the pickups farther from the strings.
Which is the final point it seemed the tone improved too! sx pickups tend to have a distortion if you really dig in, but by moving them away with the stronger magents that effect was minimized and the tone seems to have more clarity.
So needless to say I'm totally tickled with my hotrodded pickups. I'm sure you can buy really nice hot pickups from a variety of people, but given how cheap a few magnets are and how much aftermarket pickups can cost, I really don't see any reason NOT to try the magnet thing. If they don't work work for you, then that's life and you can go buy your $200 pickups. But for me magnets were not only worth the try, but worked out great.