I've always heard that Matrox cards were the best for general computing and graphics work (essentially, the best cards for anything but games), but I dismissed a lot of that talk as marketing or fan hysteria or whatever.
But, I just got a new P650 card, and I must say I can see a visible difference! Everything is brighter, more colorful (even after calibration), sharper, and somehow more...steady (can't explain it, it just looks that way). And I used to have some vague color fringing towards the very top of my monitor, now that's gone.
Plus I've noticed a marked speedup, and it even seems to have fixed that pesky 'tiny web icons not loading' problem with IE6.
And I haven't even started exploring the billion-color plugin for Photoshop that ships with it.