I've sailed an MC Scow a couple of times (I assume this is what you are talking about?). I can tell you that relative to each other, both boats feel very similar up to about 10 degrees of heal. After that, the Scow QUICKLY starts to loose righting moment and starts to turn over more quickly. You won't have that sensation with the cat because it maintains much more righting moment at high degrees of heal and it looses sail power as it gets higher (I presume because of "ground effect" as the sail gets closer to horizontal). You'll be quite surprised how much heal you can maintain on the cat relative to the Scow. HOWEVER, it is imperative that you can quickly uncleat the main quickly and easily. We rarely sail in trapezing conditions with the main cleated - I only cleat it just to free up a hand during tacking manuevers or when sailing downwind. Which brings up another point...

Downwind on a main and jib cat the mainsheet is left cleated - mast rotated 90 degrees and the sail set to carry an apparent wind of about 90 degrees (a tale mounted on the bridle or masthead is usefull to get accustomed to this). You work the angle of the boat to the power you have...if overpowered, you steer deeper to depower...underpowered, you steer up. That's a simplified example but as you become overpowered and steer down, you'll find that your apparent wind will remain the same because you sped up with the increase in pressure.....ANYWAY...downwind, cleat the main and steer to the power and wind angle you have.