Anyone use those coax to toslink digital converters?

[centurymantra]

I currently have a situation where I could use one of these to facilitate some gear. The only ones I've seen look pretty cheesy and seem to be flimsy plastic boxes. Maybe they don't need to be much more than this, but was wondering if anyone's used these things or would be able to tell me if it's even advisable. Are these things gonna pass clocking signals OK...any possibility of digital jitter/degeneration?

Thanks in advance for any tips!