Sapphire's HD 3870 X2 Atomic is the fastest HD 3870 X2 card money can buy you today. Unfortunately the extra performance gained from the overclocks is not as big as one would expect, but still, it's the fastest X2 card. For less experienced users who do not want to go into overclocking, but have a fat wallet, this is a great choice because it gives you high performance and the bragging rights of watercooling. Sapphire's watercooling solution works extremely well and feels like a solidly made product. The fan is exceptionally quiet and also controlled depending on temperature. Typically watercooling fans run at a constant speed which often makes them noisy when not much cooling performance is required, good job here, Sapphire. The biggest problem I see with the external watercooling unit is that you need to have a certain amount of space in your case for it to fit properly. Please check if your case can fit the cooler before you buy.
One reason to wait a bit with your purchase is that this month both AMD and NVIDIA will launch their new high-end products, which will certainly have very competitive performance and pricing. Sapphire's package is exemplary of what you can do if you want to present a product as ultra high-end. The metal case looks just beautiful and there bundle is about as good as it gets.
Overall I would suggest the Sapphire HD 3870 X2 Atomic Edition to everybody who wants the latest and the greatest with money being of secondary interest. If you want the best bang for the buck, then the Sapphire card is way too expensive. With the latest price drops you can almost get two aircooled HD 3870 X2s for the price of one X2 Atomic.