KellyController sells some very hardy brushless ebike controllers. My favorite feature is that they sense current to the phases instead of from the battery. This basically means that you can hold the throttle on full at a standstill and you wont ever fry your controller. Pretty much the only way to fry one is to get a bad one, dead out of the box, or miswire it. They offer a 1 year warrenty and a 1 month change your mind thingy, where you can send it back within 30 days if you dont like it.
They also have rather helpful technical support, as far as i can tell the guy that does it for them speaks correctly formed english, but his accent is a little thick so sometimes that part is a little difficult. They really arent that much more expensive then the crystalyte you started with, but the quality appears to be night and day. I would recomend that you get the ebike assembly from them while you're at it, since it will eliminate incorrect wiring that you might do yourself.
Or you could just replace the fets in your old controller. Ebikes.ca sells them, or you could check digikey/mouser/newark