Okay, razor or scissors, which is superior? Well the answer is they both are, and the deciding factor is your hair type and what you are trying to achieve. I am lucky enough to have both skills and use them accordingly. I mastered a razor before I mastered scissors, and therefore possess enough knowledge to help you decide which may be best for you.
Your first consideration should be your hair type. Is it fine? Straight? Thick? Curly? These are the first four points to consider. Generally most stylist's shy away from cutting fine hair with razors as the sentiment seems to be that it can wreak havoc on fine hair. Not so fast though, as all stylists are not created equal. The razor can be an excellent tool for fine hair if used gently on the ends only, without removing too much weight above the cutting line, or perimeter. If your stylist is gentle and insightful and follows these rules, you may end up with a cut which has a little more softness and texture on the ends, and that may help your cause. Stay away from pixie type cuts exclusively done with the razor if your hair is fine, trust me, you will thank me for it.
Straight hair will also benefit from using the razor, and in these cases a combination of scissor work and razor will yield the best results. If your hair is super thick and straight, the whole haircut can be done with the razor and the scissors can be used to clean up the overall shape. The advantage to having a razor haircut when your hair is straight is that the razor will introduce movement and texture and give your hair a little more "oomph" if used correctly. So if movement and softness is what you yearn for and your hair is straight, then ask for the razor. If you like the long blunt look which looks well kept, then the scissors will be your friend.
Thick hair can really benefit from having a good old fashioned razor put to it, but with caution, as thick hair tends to be on the naturally dry and frizzy side, and the razor will exaggerate that problem for you if you are not careful. I like to give my thick hair clients a precision haircut with scissors, and then slowly remove weight through out with the razor thus creating a beautiful overall shape which still has the benefit of having the weight taken out. Thick hair is a great candidate for both scissors and razor because there is so much hair to work with that both have their advantages.
For a very long time, curly hair was a no-no for razor techniques, as 1980 inspired hairstylists went to town on women's manes creating hairstyles that were more akin to hair bands then they were to beautiful wearable hair. We have evolved since then, and for women with crazy thick curly hair the razor can be used to alleviate volume and thickness especially underneath the top layers of the hair. This is a technique which needs practice, and it shouldn't be done by a novice, but when executed by a pro, it is a liberating feel for women who have the god given problem of too much hair. Because the razor can cause frizz, I don't recommend it to cut the length of curly hair, as the scissors are far superior here. I also don't recommend using it on fine curly hair, as in this case a stylist with scissors and some good channelling talent can give you an easier cut to work with.
One thing to keep in mind is that no matter how good your stylist is, razor cuts should not be done every single time. The very nature of this method intends for stylists to cut the hair with scissors every 2 or 3 times, so in a real life scenario you should never have more then 2-3 razor cuts back to back. This is based on a schedule of having your hair cut every 6-10 weeks, as I am hoping most of you do. So the debate isn't as cut and dry (no pun intended) as you might think but hopefully this knowledge will help you decide which method suits you best.