Its supposed to make it easier, because you dont have to use as much energy to play notes, so its easier to play quicker. The reason people say its harder is because Yngwie Malmsteen once said in an interview that scallops make it harder to play, but thats not true. I scalloped an entire fretboard once and I didnt like it, but some people do, so its partly personal preference
Its not too hard, just take your time and be careful. Take off a little wood at a time, because you can always take off more but you cant add it back. You can draw a line on the side of your fretboard for even depth to help you
If linking to other forums isnt allowed, Ill remove this link, but here's a very helpful scalloping thread
http://www.ultimate-guitar.com/forum/showt...d.php?t=1059109