With a regular glacier helicopter landing you also get far more ice than with the glacier dog sledding excursions. Also for clairfication- you DO NOT drive your own sled, like implied above. You are in tantun with a driver. You can ride the breaks or ride in the basket. You are not making the decisions about commands.
If you want true dog sledding, head up in the winter and take their dog school classes. I did this a few years ago and experienced 3 trips since then.