I find that two peoples rolls are never the same...
In my experience with teaching people to roll, no two people I have seen have exactly the same roll. When teaching people, I usually start with the C to C role because you can break it down into small steps that people can understand fairly easily. I often find that if someone does not do well because of lack of hipsnap in the C to C, that the sweep roll works well. Regardless, three things are needed to do a good roll no matter how you do it. Drive with your knee, commit to the roll till you are all the way up and make sure your head is the last thing out of the water. Lose any of these, and the roll won't happen, or if it does you are lucky and it feels icky. The head thing is the major barrier for most, though if you are having major issues with your hipsnap then focusing on driving the knee on the side you are coming up on throughout the roll is crucial. The hipsnap is not just one quick movement, it must continue throughout the roll till you are all the way up and in a stable position. I can't count the times where I see people get 3/4 of the way up and the slack off on this and flip back over.
With this said, I find that most people take what they learned with the roll they were taught, and change it to their liking. Some like to do it totally tucked forward, some like to do it all the way back (me). Some like to feather the paddle as they come up and switch direction spontaneously to get more grip. This will even change when you switch boats, as different rolls work better for different boats. For instance, I find that Riot boats tend to favor a more stern oriented roll, since the wide part is in front of the cockpit for the most part. But when I switched to the Delirious the opposite was true, plus the stern was super slicy, so if you leaned back you stern squirted as you were coming up and it was really hard. So in the end, figure out what works and keep with it. You'll probably lose your roll at some point and have to re-learn it (almost every boater I have talked to that has boated for at least 3-5 years has had this happen to them). But you just gotta remember to keep those three things in your roll, drive with the knee, finish the roll, and keep your head down, otherwise it is entirely up to you. Hope that helps,let me know if you have any questions about what I said or if I left anything out that you need explained.