Assuming you've got them set up correctly, the Shimano SLR brakes (I've tried 500LX, LX and DX) all work very well. Pad-wise I generally use Aztec pads, but have used Fibrax and Clarks and they work ok too. The SLRs have minimal maintanace on my bike, which gets used 5 days a week rain or shine and they still haul me, my lardy touring bike and set of big panniers up no worries.
I dunno what the fuss is with fancy cantis really, to me it seems to be in the lever design. I ran the same set of cantis with a 300LX lever, a Kona Curve lever and an XT lever. Without doubt the XT levers were the best and transformed the brakes beyond belief.
SP