Behind seat water bottle holders, Recommendations?

I would like to add two more water bottle mounts to my road bike. I was looking at both the Profile Design mount (http://goo.gl/53u7jl) and also the Xlab carbon wing (http://goo.gl/LPiiQ) The Carbon wing would not only add two bottles but also consolidate my flat kit/tool storage. Does anyone have experience with either of those kits? Any other options out there? The Xlab kit is expensive but looks to be designed better than the Profile Design.