Well on the sales front they usually don't know anything more than whats on the box.
But in terms of warrenty claims, they'll be spot on. Unlike a cam shop who would scrupilise and argue over every last thing (even though it doesn't come from their pocket) they just say 'yeah OK' and fill in the form to send it off/replace it.
once had a string of 3 compacts over 2years from comet, when something went wrong with it, took it in, they send it away to be repaired (because older than xmonths) comes back fixed, but looking like it was opened with a hacksaw, so they instantly refunded full asking price or offered credit for a similar compact.
Really nothing to worry about with them, and if the price/product is right, by all means get it.