Now, taking all that into account, I use Continental Grand Prix 4-Seasons on my commuters. I made the choice specifically for their wet weather grip. Once upon a time there was a magazine article with wet grip test results. Accordig to that artticle, 4-Seasons were the best.
That said, I agree that pilot error needs to be taken into account. I've had disc brakes on my four-seasons all-conditions commuter for over six years. They are no more "powerful" than rim brakes. Either type can lock the wheel. Where they shine is modulation--control. They can be very finely controlled through impending lockup. Given their greater control, it's plainly seen that locking them up isn't a failure of the brake, it's a failure of the hand upon it.
So dust yourself off, and get some panic stop practice in. Both to get a feel for the brake, and to retrain your hand. Also, learn how to shift your weight back when stopping. Together, it'll significantly reduce your chances for face-plant. This is good advice for all brake types.
Thanks for the recommendation and yes, you're right about pilot error. :-) I guess my old bike's rim brakes were in poor condition or poorly adjusted so I never was able to lock them up. Also the fact that I'm left handed doesn't help. I did adjust the disk brakes for a 'winter setting' so that they don't lock up as quickly anymore. The rear brakes offer plenty of stopping power, after all.