Nobody ever complained about Steam's Valve laggy servers, because they DON'T HOST any games in the first place. They allowed any schmuck to host their own servers, pet clan servers included, and publish their address inside the service, so you can find them.
So, when you are invited into a clan match, you know your lag is your fault. And, when searching games outside a clan match, you know the search algorithm will give you the list filtered by criteria, being one of them the lag. Given Steam works in over 130 countries, the search will always give you the geographically close, privately owned, open servers with the best lag possible (most of them are ad-ridden, there is no free meal after all).
So yes, Steam may even have public servers, but you only get to connect to them when no other server is closer to you. Now, Microsoft is shooting her own foot trying to host a large number of simultaneous games played by Xbox owners across the globe and won't let anyone host their own games, using her service just for matchmaking.
Sony released the beta, free download version of Ace Combat Infinity for PS3 a while ago. Except the games were all hosted exclusively on Namco Bandai's servers or whatever. Upon closing the servers, the game just stopped working, presumably to return by the end of this year as a finished product (the game was fantastic by the way). This sort of dick move is the intention of Microsoft, perhaps... they can pull the plug and hose their players if things go wrong.