disk break recommendations from mountain bikers

[jknakes]

I've had a cannondale rize4 since 09 and have ridden on and off. i've never been a huge fan of the Hayes stroker rydes that came on it. they work but they're noisy, i don't feel like they have very good modulation, and recently riding mostly at trail that has a lot of silt due to proximity near a river, they feel like they grind. i've tried switching between a few different kinds of pads, but i'm still not very happy. just wanted to see what brakes set ups others are using and how they like them. right now from searching around online i'm thinking about doing the shimano slx m675's. I've also found shimano xt's and xtr's on jensonusa for reasonable prices. i'm guessing those are probably left over older models. Any input would be appreciated. thanks