Its more that the patch was really nearly 1Gb of new files so when it was preparing it worked out 5Gb of the patch already existed and downloaded the rest.I started mine then went away for 5-10 mins and then it said 6.1/6.9 done so assumed it was fast....then it slowed to a crawl and took an hour or two to finish.
I can only assume their CDN sucks, I would have thought it all uses Sony's but apparently not.
Mine was pretty quick too - think preparing took longer
ps3ud0