If he just purchased the game, the only update he'll have to download is the last one since that patch contains all previous patches plus the latest one (as does all PS3 patches).
But the download is about 420 Mb in size if I remember right. So there's 2 things that can determine how long it takes to download it. That being your own internet connection and it's download capacity and also the current server load/capacity of the patch server. So if you're downloading something else on a PC in your house, it'll take a while. Or if the patch server is overloaded for whatever reason (or just not allocated for much traffic currently), you'll get slow speeds also.
Thankfully you'll only have to d/l the patch once and then you can play anytime.
My connection does it when I drops right down. Tried to D/L Borderlands DLC on a bad connection once, apparently it was gonna take over 3 days to complete. Downloaded it in half an hour a week or so later.