I suppose you are just polling for opinions since "worth the expense" is completely subjective.

I haven't done the helicopter trip because:

a) it costs too much

b) it makes noise (I believe overflying the Argentine side is banned for that reason)

c) I can't image the views would be that much more novel or exciting.

I took the helicopter ride a few weeks ago with my cousin and my 10 year old son. None of us had ever ridden in a helicopter before, so we all were excited to go.

I enjoyed the experience. I think that seeing the falls from above IS worth it. You get a much different perspective from the sky.

I've seen videos of previous helicopter rides. I think that the helicopters used to be able to get much closer to the falls. Now you fly well above the falls. (If you're expecting to get up close and personal, you'll be disappointed.) But we still thought that the view from above was worth it for us.

I have just come back from the falls and the helicopter trip was about £60+. The flight was short (about ten minutes) and you do not go right into the falls, but I thought it was worth it. The overall view of the falls from the air was wonderful. I have never flown in a helicopter before and so I enjoyed it even more.