Is the only difference in a roller cam/lifter set-up that the lifters have rollers on the bottom that touches the cam, just like the only difference between std. rockers and rollers are the little roller at the end? And do roller cams have better (or maybe quicker is a better word?) rev capability?

Taylor,

NO,
and, Maybe....

UDHarold

No the roller lifters are not the only difference. The cam is tottaly different from a regular cam. It has a straight edge instead of a slanted edge, so that it doesn't cause the roller lifter to spin like the regular lifters. Advatages are less wear, more h.p., and extended parts life.

Taylor,

OK, here goes.......

When you look at a cam, what you're seeing is the lift curve WRAPPED around the base circle, and this curve was cut out by a LIFTER-SHAPED cutter. It has a flat bottom for solid and hydraulic cams, and a radiussed-bottom for hydraulic roller and solid roller cams.
Companies used to, in the 60s, offer the identical lift curve for solids and rollers, and the cams looked differently, but gave the identical lift curve.
Flat-bottom lifters, for solid and hydraulic cams, are limited by their diameter to how fast a rate-of-lift they can run. As the rate-of-lift gets faster and faster, the point of contact between the cam and the lifter moves out towards the edge of the lifter. If the rate-of-lift is too fast, the point of contact moves off the lifter and the lifter digs into the side of the cam-----Goodby, Mr Cam!
Roller cams aren't bothered by rate-of-lift concerns, but they are controlled by how fast you change the rate-of-lift, or acceleration. If you accelerate the valve too hard, cutting out the cam makes a big DIP in the side of the cam, making it very hard to manufacture.
In a Nut-shell, solids and hydraulics are not bothered by acceleration-rates, but are controlled by max velocity, or rate-of-lift.
Hydraulic rollers and solid rollers are not bothered by rate-of-lift/velocity, but have maximum acceleration rates that make them hard to make.
This is a little to answer your question, but it's really a lot more complex than just this. I've been working on this for 32 years, and I'm still learning......

UDHarold