They added a shitty blower card to start prices at $379. I don't remember that type of card for the 900 series. Then they added $20, $40 to all the other cards. Add in the jump in price from $349 to $379 and it seems a lot more expensive.
The Windforce has lower factory overclocks out of the box than the G1... maybe by 50~100Mhz? Need to check on the official specs. You can use the Gigabyte software or MSI Afterburner to clock it higher yourself.
The difference being the Windforce has 2 fans and the G1 3 fans, theoretically the G1 should keep things temps lower and more stable overclock, but a number of reviews now have said that the voltage is locked on the 1080/1070 cards and that the temps never get high enough to lower the clocks, so maybe 2 fans will be sufficient. Hard to be definitive until actual reviews come out.
Probably gonna wait on Windforce reviews.
Might even just say fuck it and settle for an Aero.
The last true blower I had though was an 8800gt back in 2007. It was loud as hell, but it was also packed into a Dell case with a really weird motherboard and overall configuration that had some pretty poor air flow.