Takes a while to do a decent review. There are meaningless but instant “Ooh, I love this X!! (Now gimme what you promised…)” reviews just to put out a “positive” review, or those where you actually use the X in question, but it takes a while.
I’d doubt anyone would refuse a PP refund until you put up the review. If you get tired of waiting, you can always return the thingy. And being in a sour mood, you might be tempted to post a negative review. That’s not nice, either, but it’s possible.
I don’t recall if I ever did one of those “refund-by-PP” review dealies. I was approached to do one, but didn’t have any PP account, had no idea how it’d work, etc., so I think that just fizzled out.
But even so, I’d be interested. I’ve pointed out both good and bad things in reviews, so I like to think I’m fair.