PSN for me.
I have and used both and for DL speeds, i actually get better speeds on PSN, except on Tuesday nights when the update goes up. Then i don't even bother until the next day, i assume everyone on PSN is DLing all the new content at once for that.
Price, your right, you get what you pay for. And i pay nothing for PSN and get most of the features that Live has anyways. Party chat might be alright once and in awhile, but it was never a draw in for me.
User Interface/XMB - Again i rather PSN user interface, i find it's more smoother and easier to find content,the store is right there for me to click on as i soon i boot up. I can't stand scrolling through menus and IGN strategize windows on Live. (just a personal preference)
And why do i have to create a cheesy looking avatar on live? Granted, Sony has Home and there avatar system but it's not forced on the user. If i wanted an Avatar, i'll click on Home and create one, Live forces you create and dress this lil guy up before i could create my Live account.
I enjoy the intergrated Trophy system more so then Live's GS points. I like leveling up with the different types of Trophies and just feels more accomplished to me.
However i will say that Live's loading on the XMB kills PSN, PSN's intial loading of Trophy icons is pathetic!
PSN plus although is a paid service and although i haven't jumped the gun on it yet, it seems to worth the price tag considering the content you get back with it. That's just from on the surface reading up on it, maybe my opinion will change once i actually experience it.
I always have a steady connection and rarely get disconnected from either service, unless there's a storm here and everything goes down.
Tied in with the price agruement is the extra media app's question. Since PSN is free, app's just as Netflix, or Facebook intergration is a given with no price other then that's vendor's subscription. (Netflix) But on Xbox Live, i need a gold membership to access Netflix, Facebook, Last FM etc. That to me is to quote an earlier poster "a ripoff"
PSN Internet Browser - I know i know, the quality of this thing is crap! But it gets the job done. When the g/f is hogging the PC and i need to find some info or even come to this site, the browser on PS3 gets it done, while Live doesn't have one at all.
I can't think of anything else at the moment, but that pretty much sums it up for me. Like i said, i have and enjoy both, but for the personal fav of the 2, i have to go with PSN.