And that's why XBL is not open, my friend. Technical issues may be part of it (e.g., single sign-on for third party games), but they are seldom show stoppers. User generated content is another stigma too.
That's not an xbl limitation though, that would be a Microsoft decision. Sony is identical in that regard, they aren't really 'open' as they will not allow just anything on there, it has to meet with their business goals. You can have multiple sign ins, EA has that already, although I loathe that with a passion, it's just more obfuscation that should be eliminated but that's just my opinion. You also have indie content remember, me and you can very easily make a game and put it up on live, easier than it would be to do so on psn. There's tons of user generated indie content in their indie section, far more than on psn. In the end something like steam would be treated the same for both Microsoft and Sony in that neither is more open than the other because of their services, it's all about if it meets their long term goals otherwise it will never happen no matter how open a platform claims to be. I'm not really sure why anyone calls either one open really because they aren't. The PC is open, the 360 and PS3 are locked up tight.
As for the best stuff on PS3, I see Demon's Souls, Valkyria Chronicles, Tourne, Blu-ray, MGS4, etc. I think we can find gems and turds on both shores. I think Gran Turismo 5 and The Last Guardian may be promising also.
Well I didn't mean games, I meant everything other than games, all the other related items that make up the console. They are behind in just about everything that Japan is in charge of. Online experience? Terrible, far behind the competition. Movie delivery? Weaker than the competition, which is incredibly bizarre as Sony own a bunch of movie studios so how they fell behind Live on that is beyond me. Indie game support? Very limited compared to the competition. Firmware and game patching? Horridly slow, far worse than the competition. Voice chat in games? In general, far behind the competition. Tools and support? While Japan was in charge, utterly appalling. With the west in charge (Naughty Dog), significantly improved although still not up to the competition but that's only because ND are also busy making games. Etc, etc... That's what I meant, on the software infrastructure that makes the console what it is, Sony are simply not keeping up with the competition.
I really think Sony need to look at themselves in the mirror and recognize their strengths and weaknesses. As a hardware company they are great. Sure everyone has an 'rsx' moment every now and then where they bollux something up, but generally speaking they excel at being a hardware company. They have tons of ips, games and movies. They have a strong brand name, brick and mortar support, etc, all the other things they have in their favor. But as a software company (not games, all the rest) they just can't keep up and it's really handicapping them in the grand scheme of things. They need to recognize that and partner up with someone to help them out.
I also don't think your achievement example is universal. I play PSN online and my achievements come fast (e.g., sniping the 50th Rapid Assault dude earned me the "Screeching Halt" achievement immediately).
I've never had the pleasure of an instant trophy, they have always been delayed. But irregardless, it's yet another inconsistent psn behavior that is a non issue on live.