1080 TI - new best bang for buck?

[r9290xocl]

imo a best bang for the buck should also consider other factors like temps, power consumption, time it takes to crack, reliability, and so on.

Temps of the GPU do not matter. If the system is stable and you don't care about the noise, turn the fans up and everything is fine. If you have a Founders Edition and 3 years warranty you simply cannot overstress it, since the power limit is setting the right limits.

Power consumption is always an important point and correlates with the amount of heat produced by one card. The latter may only matter in bigger environments like server rooms, but energy can be a serious factor in 24/7 hash cracking. In Germany a rig with 4x GTX1080 Ti and an efficient PSU easily consumes 5 to 6 bucks a day.

With NVidia, every new generation uses less power for the same performance as the old one. An old GTX980Ti e.g. is slower than a GTX 1080, but uses 40% more power. So new is always better in energy terms. And since the performance of a GPU generation scales very good under hashcat. 30% more performance result in 30% more energy used.
A big difference in systems can be the PSU, so if you plan to heavily crack hashes 24/7 you better invest in a Titanium or Platinum PSU instead of a Gold standard (and don't even think below that anyway). The higher price will be drawn in over time, even at only two percent difference in efficiency.

Reliability depends on many factors, but along with NVidia the reference cards respectively Founders Editions are pretty much in the same ballpark. One might have better experience with a special manufacturer, but from my experience the more important question is: how fast and uncomplicated do they change a broken card?

The time to crack can be crucial for some if you have limited time sets to be played. E.g. checking passwords in an ISO27001 audit usually defines a certain amount of time, like 24h, where the quota of cracked password specifies the quality of the staffs password creating ability. The more cracked the better.

You kind of reinforced my point: best bang for the buck is not just about hash/$