Even though the naming suggests otherwise, the biggest strength of the MSI HD 6850 Cyclone Power Edition is that its fan is able to run extremely quiet when the "silent" mode is engaged via the little switch on the board. I would actually go as far and suggest the silent mode to all users, no matter if they overclock or not. In idle there is virtually no difference in temperature or noise between both settings, but under load the noise difference is well audible and temps go up only by a few °C.
In terms of performance MSI did a good job as well. The overclock out of the box is the largest available on the market so far. Other AIBs offer cards at 820 MHz, but MSI has chosen to go all out and specs their card at 860 MHz. This makes it easy for users who are not willing to do manual overclocking to get the most out of their card: about 8% faster than the reference design. Additional overclocking potential is there, but the maximum you can reach via own overclocking is about the same you could reach on any other HD 6850 card. Voltage controls in Afterburner are nice, but fairly limited up to 1.3 V.
The bottom line is, if you are looking for the quietest possible HD 6850 experience, then the price premium is worth $20. It is also reasonable if you are too lazy to do any overclocking yourself and just want a fast card out of the box. For willing overclockers, who can live with some fan noise, the $20 price increase seems a bit much, especially since MSI does save considerable money by using a cheaper VRM solution than on the reference design.