HydroTail vs XLab Carbon Wing

So my friend is stoked (excited) about getting this new rear hydration bottle holder the Beaker Concepts HdyroTail (He won the winning bid at a charity auction). He says it's the lightest therefore the best on the market. Can anybody who's used it corroborate this from first hand experience. Is it that much better than the XLab Carbon Wing coming out? My thought that even though the HydroTail might be lighter the XLab Carbon Wing seems to offer a lot more utility options. My belief is that both are very nice and the "best" one is relative to your needs.



Thanks in advance for any comments or feedback on the Hydro Tail "hydration system".

As always here's a link to the products:
HydroTail by Beaker Concepts
Carbon Wing by Xlab