I heard good things about the jumbo lip pencils too and decided to give one a go. I picked up one in the shade Burgundy (I've got a great fondness for the berry shades!)
That being said, I don't think I'm going to be buying anymore of the jumbo lip pencils. This is only a personal preference of mine, not that there's anything bad about the product. The round lippies are virtually the same texture and are cheaper. They are also smaller and hence easier to slip into a small pouch to carry around. Yes, the pencil would be more accurate in terms of application because of the tip, but I carry around a small lip brush for such purposes.
All in all, it's an awesome pencil. But it won't work as a lip liner as it's too creamy and soft and personally I would rather carry around a lipstick than a pencil. I'm going to be using this one a lot while it lasts though!
Pic of the lip pencil in action :)
I so need to tame that bit of stray hair!!!!!