Also a few more things to consider, higher your wingloading means that you travel down your glide path quicker, the faster you go down your glide path the less time the prevailing wind has to push you even further. Have to go downwind with the prevailing to go as far as possible.
Am more experienced with paragliding than skydiving, but can you gain any height on a XC flight but use of thermals, convergence, wave conditions as they use in paragliding with the skydiving canopies? Am assuming so even if your unable to use them as efficently as other types of wings.
Ramble over :)