The out of the box setup on the HD 3870 X2 is pretty good. While the cooler is a little loud, it doesn't come as any real surprise considering what the cooler has to cool. The card is clearly for a niche market with the main target audience being users of 1920 x 1200 monitors and above.
If you're on a 1680 x 1050 22" wide screen monitor we would probably recommend something from NVIDIA like an overclocked 8800GT or an 8800GTS 512MB. The gains that the X2 gives at the resolutions below 1920 x 1200 just make it an absolute waste of money for that audience.
Dual-GPU cards or just dual-GPU setups in general are going to have issues. With the games needing to support the technology, the jump to a multi GPU setup can offer limited to no positive impact on your gaming experience.
If you're on a high resolution monitor and you want to crank the details up on those Source based games or Unreal Tournament 3, then this card is a fantastic option. The price is good and the performance increase when the resolution is set so high is great. On the other hand, if you're expecting to play Crysis at 2560 x 1600 you're going to be severely disappointed.
The Sapphire offering isn't anything fancy, but it does what it needs to do well. The bundle is pretty standard with no included game, and considering we've already seen HD 3870 X2 offerings with aftermarket coolers and more DVI ports it doesn't stand out too much.
The bottom line is that if you don't need all the fancy extras that these other cards offer, the X2 from Sapphire is a better option due to the fact that their method (as with a lot of other companies who follow the reference design) keeps the price down.
The X2 is a good card, just don't expect it to be the be all and end all of performance computing.