To follow up on the discussion here, here is a quote from an article in Tradition by Prof. Chaim Waxman (If it's in Tradition it's got to be true. Tradition even has footnotes!!):
"It is neccessary to distinguish between two types of modern Orthodoxy. One may be called philosophical, while the other is more appropriately characterized as behavioral. Within the category of philosophical modern Orthodox, or centrist Orthodox, would be those who are meticulously observant of halakhah but are, nevertheless, philosophically modern. Within this context, being modern means, at minimum, having a postive perspective on general education and knowledge, and being well disposed to Israel and religious Zionism.
The behaviorally modern Orthodox, on the other hand, ore not deeply concerned with philosophical ideas about either modernity or religious Zionism. By and large, they define themselves as modern Orthodox in the sense that they are not as meticulously observant as the right wing states one should be. "
(Link). While Prof. Waxman grossly overstates things, there is a kernel of truth in what he says, in my opinion. This does not mean that UO communities are better than their MO couterparts. Judaism is not merely a religion of laws, and "meticulous observance" is not the sole basis on which a community should be judged. To take one example, the UO community's rejection of R' Slifkin was a heck of a lot worse than improper hemlines.