They both remove the hair the same way by plucking more or less so the whole hair is removed which is what you want. Waxing is a fast ripping action over a large area.. slow or fast ..this is the problem I have with it.. it's just too much instant pain or drawn out intensity.
Epilation is slower and more manageable, you can choose how fast you run over the skin in line with your pain tolerance, and with time you get faster at it. I like the buzz of the epilator against the skin it stops you from feeling the plucking as much, after awhile as you get used to it you only feel the buzz against your skin more than anything else. The first time I used it I was like "wow I can feel that", but after time you get over it, same with waxing but for quickness and convenience epilation is where its at.
Sure some areas of the body are more sensitive but over time you can build up to them and inch your way into them. My housemate is already able to do her underarms with it!! I'm not that hardcore though... not yet
Highly recommended over waxing ^_^