This is actually a really killer setup and I think that over the past few years we've seen a shift where SLI was only something you would make use of when using the highest end cards to it now being a technology that strives in these mid-range models.
The real back and forth motion between AMD and NVIDIA in the pricing over the last few years means that the mid-range models have seen aggressive pricing and just some awesome performance in single card form. When you combine that single card bang for buck experience and double it, you end up with a really powerful setup that doesn't cost the world.
Sure, in the end it's not as good a value as the same card when it comes down to the pure FPS, but you're talking about a setup that plays 1680 x 1050 easily and performs here and there at 1920 x 1200 to a setup that plays 1920 x 1200 easily and performs here and there at 2560 x 1600.
If you're gaming at 1920 x 1080, this ends up being a really great setup for you and because the pricing of the higher end models aren't as aggressive, the dual card setup ends up being a better buy than the single higher end one, and that's what we're seeing here today.
SLI, at least in two card form, really causes no headache. Now if you've got a compatible motherboard you can get performance equal to and sometimes better than a single GTX 570 for less. The great thing about the Palit offering as well is while it does run a little warmer, it's only because the fan speed's so slow that the setup is near silent.
When you think about it, having the same performance as a HD 6970 or GTX 570 with almost no noise is just a dream for some people. Obviously the noise factor is going to change from manufacturer to manufacturer, but the silent path that Palit has chosen I think pays dividends to the right crowd.
In the end we've got another great GTX 550 Ti with a 1GHz core clock. What we've also seen here today, though, is just what the model is capable of when paired with another. This is indeed a really attractive option for people who want power and silence while having a bit of fun with SLI at the same time.