The audiophile 2496 is indeed a nice card (at 4x the price of the chaintech) but it does not, to my knowledge, have toslink (optical) out (only coax).
I've confirmed through several different tests that my chaintech av-710 does not resample the digital output. The simplest way to check this is to see if a surround receiver can decode a dts-encoded digital signal. If the digital signal being fed to the receiver has been manipulated/resampled, you'll only hear static.
Further, through a simple bios flash, the chaintech av710 can be "converted" into a prodigy 7.1 and can then use the full asio driverset available for the prodigy.