Sightseeing flights in Palau?

Has anyone done sightseeing flight/helicopter in Palau? I'll be there in December and want to see the 70 islands. I see Palau Helicopters and Belau airlines offer tours. Which is better, helicopter or plane (much cheaper)?

You may not have a choice.
A friend of mine who wanted to do this earlier this year ended up having to wait several days as there was no one else interested in going on those flights. In the end they felt such a pity for her that they took her out alone!
So just go with whoever takes you.

Belau airlines no longer exists. I have heard of helicopters being available to rent, but didn't realize there were organized helicopter tours.