You mean the midi grooves that come stock with drum VSTi's? Yes, they have a more real feel right off the bat, because someone actually played them on an e-kit. So, timing and velocities will be more realistic.
You can create the same thing manually by programming, it just takes a lot longer.
Drum loops usually don't contain like beginning, verse, bridge, chorus etc. so they are pretty useless. And like nezvers already mentioned, they are stereo. I posted this video before but if you haven't seen it, watch it.
Thanks guys, yeah I was looking at drum loops (non midi) They actually have multitrack ones now, but you are also stuck at whatever tempo's they are at.
And with midi loops you can always modify them e.g. more kickdrums, less kickdrums etc. Eventually I learned how to program midi loops my self to sound more realistic. And there's a lot of videos on youtube about drum techniques to study. Once you learn to think more like a drummer the better it will sound. Oh and forget that the humanize function in drum plugins are enough. You still need to work on the velocity. Nothing is more boring than programmed drums and everything is static.