I would much rather have a 5850 over a 460. Out of the 5750, 5770, 5830, 5850, 5870, 5970, 460, 465, 470 & 480, the 460 and 5850 are the two best buys. You can aruge that a 460 overclocks to the same performance as a stock 5850, however, both the 5850 and the 460 are the coolest running highest overclocking cards of this generation.
The 460's strong point is its value. At $210 it has a better price/performance ratio than the 5850 now that the 5850's price has risen from $259 to $300.
The gtx460 is a great overclocker, but the 5850 overclocks to the moon as well and with a 1000mhz OC can reach a stock GTX480 - something that could definitely not be done by a 460.
However, for the money (even with slightly less performance) the 460 is the clear winner over the 5850. Pricing is what makes this GF104 card a winner.