You'd actually be surprised about how good their accuracy is, and even more so their reaction time. Their weapons are almost always pointed in the right direction, and they just move faster than the normal Marines and Army infantry.
Their gear is better, but not all that much better than an average recon team. Their Intel is better, in that they are fully briefed on it, rather than the chopped down versions the regulars get.
The biggest difference is their training and lifestyle. They don't have to deal with the bullshit that regulars do, don't have to play stupid games. Their job is to be good at their job, so that is all they do. And because of all that training time, because they can focus without being pulled into a working party or parade duty.