Sram makes good stuff. I've personally never owned a bike with Sram components but know numerous people and shops that swear by them. They trade blows with shimano for sure.

Unless there's been a big leap in disc brake engineering, the general rule used to be that brake pads offer more stout stopping power, but disc brakes offer more versatility. For example, on a dry day brake pads will perform better than discs. If things get a little wet or muddy the discs are the better option. Discs are heavier, and that's why you rarely see them on road bikes, but they're almost always on cyclocross rides due to the wet and soggy terrain. I've never owned a bike with discs either, but have ridden and my experience was the same. It was a dry day and they did pretty well but seemed a little weak compared to the high end pads I have on my Felt.