Is it possible you guys do not have your routers configured properly? You could have a 100meg connection, but you network is only as strong as your weakest link. If your router is not configured properly, or is an old protocol, that could be affecting your through put. Here is a blurb on electrical signal noise affecting throughput:
SpeedGuide.net :: Router speed drop solved, could that be an issue? There are a whole myriad of possibles issues that are unrelated to the PS3.
I have a 5 meg Internet Connection, and do not think that I have ever had to wait more than 5 min ever for a 900meg-1gig download.
Are you able to stream video and media to your PS3 from your home computer without any issues? If not, then your internet has nothing to do with it and it is a router/setup related issue.