Sapphire's own HD 4850 design seems to be designed with cost in mind. The card is currently the cheapest HD 4850 card available online which alone will be very appealing to many users. On the other hand for just a few dollars more you can get features like overclocking and silent fan from competing manufacturers. The new cooler Sapphire uses offers lower temperatures than the HD 4850 reference design but is also very noisy in both idle and under load. If you are the tweaker kind of person you can easily fix this by modifying the BIOS or use software to control the fan. Also the card offers very solid overclocking potential as well. Honestly the only thing that I can really complain about is the fan, but this is a major issue. If you just want to plug in the card and be done with it, you won't be happy. The fan noise will plague you day in and day out. Other manufacturers have found better settings here, most notably Powercolor who's card is inaudible under both idle and load.
Nevertheless, if you are looking for an affordable card and the fan noise is only of secondary concern to you, Sapphire's own HD 4850 design should definitely be high on your shopping consideration list.