Dior Serum de Rouge Luminous Color Lip Treatment

I was browsing through the makeup counters at Macys this weekend and stopped by Dior to look for a new lipstick.  I wasn't really sure what I was looking for, maybe a lipstick that I can pretty much wear daily that is on the pink side, but not bubble gum pink or anything blue based, something warm and neutral, maybe.  The SA that helped me tried her best to match a color that I wasn't really even sure about, and after about six colors or so I got pretty confused.  But I liked the Dior Serum de Rouge in Soft Pink Serum (#640) of what I had seen (Note: not the color shown):

It comes in a slim tube, about the size of a thick pen, not the prettiest packaging, pretty heavy for a lipstick of that size.  I asked the SA if there was anything special about this lipstick, since it was pretty expensive compared to the other Dior lipsticks ($32 before taxes), and she mentioned that it's supposed to contain a serum that fills out the lines on your lips, sort of plumps it a bit.  It's sort of a lip treatment with color.  I wasn't looking for any added benefits, but sure doesn't hurt to have something that enhances the appearance of your lips and treats it. 

I have worn it for about four days now.  The texture is creamy, the taste kind of reminds me of candy, and is medium coverage, more pigmented than a tinted lip balm.  This lipstick doesn't last very long, it slips off the lips pretty easily, especially since I drink alot of water throughout the day.  I find that I am reapplying every hour or so, not that I mind reapplying.  Overall, I'm not exactly impressed, It's not very hydrating, nor does it fill out the lines like the product describes.  I'm not sure if I should be using a chapstick under, like i normally would a lipstick?  I figured the treatment ingredients in it would replace the need for chapstick, but maybe it's not necessarily designed that way?  I probably won't repurchase, but I will continue to use it for a bit until I find something new to replace it.