In futures:
the leverage is better,
tax treatment is better,
don't have to pay the fund's management fee(which is built into te share price)
depending on the futures the bid/ask per dollar invested is better,
in a backwardation situation tons of money can be made on rollovers as the nearby goes ballistic (copper recently)
enhancement strategies with options are available.
I can see that for some long term retirement accounts ETF's may be more suitable.
Regards,
GC