Hi, my husband and I have been in HK for two years and moved to DB about 3 months ago. We loved living in Central, but found that the rents were so high and the houses were so small, we just had to consider something else. Although we weren't excited by the prospect of the ferry and were nervous about the social scene, ability to make new friends etc., I found it was exactly the opposite. The ferry runs very regularly, and you come to think of it as simply a bus ride into a major city. We lived in the suburbs of Seattle and took the subway into town, so this is no different for us.
My husband works in town, but I find that I go in about 3-4 times per week for shopping, to see other friends etc. We usually go out for dinner or movies on friday and saturday, and with the new IFC movie theater, it's very convenient.
I was pleasantly surprised by the quality of lfe and the social scene here. Although I've only been here 3 months or so, I met lots of nice people (mostly American, Australian & British expats) and find that people out here are much friendlier than on the island (perhaps because it is more isolated) and very welcoming to new arrivals. We have BBQs with friends, lots of play-dates for our kids (we have two toddlers)
IN summary, we really love Disco Bay. If I were single I probably wouldn't like it, but I think it's great for families. I think it makes me appreciate HK more than before, because we have the best of all worlds-- a great house, a great environment for our kids, good social scene, and the opportunity to get into the city easily. IMHO, it's better to be free in the "country" and make the trek into town than feel suffocated in the city and make a trek to the "country". Good luck in your search!