To people considering this 1660TI I would look at Vega 56 better card better price.
At $280 of course its a better card. But AMD hasn't officially lowered the price. As of now its much closer to $400, I don't think it has to go as low as $280 to compete with nvidia though, I'd say it could go as "high" as say $330 and still be a good choice. Now, the RX590 is supposedly dropping to $229, but I'd still get the GTX1660Ti.
I think we'll have to wait till navi for AMD to compete on this segment.