I’ve had some experience of this – I think I’ve completed a couple of warranty claims for Nexus 7s via the Google Play store recently.
I say I think, as I’ve had no notification that they’ve accepted the warranty claim as valid yet. What they do is get you to put in another order for a new device, but leave the credit card charge ‘pending’ while they send it off to ASUS for verification. No money has been charged for the new ones yet (three months on), so I assume the warranty claim was successful, but it’s hard to be sure.
So you get your replacement device more quickly, but are left in the dark as to whether they will arbitrarily decide to charge you for it at a later date, forcing you to fight to get the money back.
Both claims were screen related BTW – the infamous screen lift on both, leading to one of them cracking. They tried to reject the cracked screen claim out of hand, but agreed to send it to ASUS in the end after I ranted on about the Sale of Goods Act.