You would think it would be as easy as a yes or no answer but it isn't. Clocking and it's related specifics and problems depends on many things and the performance of any two items playing together in being master of slave are not as cut and dry as reading and mathing up the specs. So you just need to try it and see if it makes a difference in your application.
first we should clear up what you mean with "accurate"? Do you really mean the stability of the generated clock signal due to the specifications of the used clock oscillator (e.g. +/- 1ppm of the basic clock rate aligned to AES11)? Or do you think about to add a "jitter-free" clock? That are two different things.
If you want to get an improvement in sound it would be more important to add a low-jitter clock generator whereas its frequency stability is not so important.
Maybe you should redefine for yourself what you really want or need to get.
Take into consideration Christians and AGs comments but the short answer is yes..
I have seen many instances where by adding a device with a lower jitter clock and then clocking the whole studio to that, the sound of the converters improved dramaticly. One such case was when a friend who had several ADATs, purchased an O2R and clocked the ADATs to it. The sound became much more solid and smoother ... better clocks is a way to improve your sound.
I have many colleagues who have jumped into the stand-alone clocks and they all say it's made a big difference. Even though it's a pretty price to pay for most of them, each one has said it was one of the best purchases they ever made.
both of you are right, but this is really a matter of adding a low-jitter clock generator to a set-up. This effect is actually not based on the stability or accuracy of a clock signal. That is what I also suspected at first when reading DrsStudios' statement. On the other hand, a low-jitter AND frequency-stable clock should be prefered at any time.
A very low jitter and accurate master clock/sync source is a great thing to have, but...... not all digital devices can take advantage of a lower jitter input or a more accurate sync source. In some cases when you use an external clock no matter how much better it really is, it can even makes things worse. Older digital devices that can accept word clock input from a good and accurate master clock will often make a big difference. So as I said before, you just need to try it and see if it makes a big enough difference in your application.