I use a Shimano 105 caliper, and it's amazing. I've used cheap brakes as well, and I can tell a big difference. These calipers feel snappier and have better pads. Not to say cheap ones won't stop you just fine, but nicer brakes do have a better feel to them.

I'll also comment on the lever I use...Paul E-Lever. This is the worst lever ever haha. It sucks. So overpriced and the size of it doesn't let you get much leverage. It also requires you to take off your grips/tape in order to instlall or remove it, which can be a pain for someone like me that switches bars out every few weeks. I picked it up b/c my friend got a set for cheap, so he sold me one for a lot less than they usually cost.