When I first heard about PowerColor creating a completely passive HD 3870 card I expected a card that was running extremely hot and needing excellent airflow in the case for proper operation. But apparently the SCS3 design of PowerColor does a great job _reducing_ the card temperatures compared to the reference design. Yes, you read right. The passive cooler's temperatures are actually lower than the reference design temperatures with a fan. We could even do some mild overclocking on our sample.
Being completely noiseless and offering HDMI+Audio this card is an excellent candidate for use in a Media PC system that stands in your living room. Only the three slot design might limit the use since it will probably not fit your small form factor case. I also think it will be difficult finding a motherboard that has enough space for a CrossFire setup of these cards. But maybe your board has space for one HD 3870 SCS3 and one reference design HD 3870. This will still allow for a quiet solution and CrossFire.
With a price premium of only $20 over the reference design this card is really a no-brainer when you are looking for a HD 3870 card. The only exception being if you are really on a tight budget, don't care about noise or are going the CrossFire route.