I find that the whole transaction on C24 is just not fun. So I personally haven't done a transaction. And please note, I'm not criticizing the operations of C24, I'm just criticizing this specific seller, who coincidentally happens to be C24 themselves (they can sell on their own platform, nothing wrong with that).
The whole reason why C24 has this escrow thing is that it satisfies a requirement, a requirement of fairness, that you get to inspect the product. But the big fact most people don't realize is that this is only of value if you actually use the inspection time to truly inspect the watch. Most people just assume they're smart enough to not be fooled. Look at how many fake things are sold at The Real Real and other websites and people don't realize until much later... I bought a watch from an auction house that was the biggest player in watch auctions at the time, had the biggest marketshare, and I didn't realize the mistake until I took the vintage watch to the factory to be restored and they opened it in my presence to tell me it was completely wrong.
But yes, to have this inspection period gives the buyer confidence (perhaps the buyer overestimates their ability to inspect a watch) and also gives the seller worry that their bad watch will be discovered. These fears alone will discourage bad sellers and encourage overconfident buyers who don't really know how to inspect a watch. But as long as the ignorant buyer is happy at the end, and no one is wiser, the job is done!
My point is the whole business plan works well if the buyer is very ignorant or overconfident of his/her own bad-watch detection abilities.