There's a problem with all liberal forms of Judaism. In fact, it's inherent in their very being liberal. This is true for Reform and to a lesser extent Conservative but it is very much an issue with the Reconstructionists. The problem is that all these movements are saying that traditional beliefs are not true and that they must then go on a kind of salvage operation to figure out what parts can be kept and which parts must be left behind in the light of modern knowledge.
But what this leads to is a sense of a loss of legitimacy or a loss of genuineness. People don't want their religion or philosophy or way of life to be salvaged leftovers to showcase in a living room. They want to be sitting and using certified and complete antique sets. This is part of the reason why Orthodoxy is so strong today. It holds that sense of genuineness and of being "real" Judaism and not some form of Judaism-lite. It holds it that way because an Orthodox Jew can pick up a Jewish text from millennia ago and find direct correspondence with how he lives today. Orthodox Rabbis have to understand Talmudic logic, not just for heritage appreciation, but really because they apply it all the time to Halachic issues that arise.
Other forms of Judaism have to accept these same vaulted texts as meaningful to Judaism but at the same time must reject as not true often large parts of them. Classic texts are seen as Judaism's past in liberal movements, but are Judaism's present in Orthodoxy.
How to get past this apparent discrepancy and to give liberal Judaism the sense of legitimacy while still using traditional sources is a pressing issue. Ideas like continuous revelation and an evolving religious civilization are useful, but they still don't jive well with rejection in a historic religion. I'm certainly open to suggestions.