[sideshowb]

As a user of both SO and Quora I am annoyed by SO's strict policy on subjective questions. There are plenty of legitimate reasons to ask useful subjective questions, yet SO will close them as "not constructive". As far as I'm concerned this is a crude heuristic, it maintains good content quality at SO at the expense of prohibiting certain kinds of discussion.

It's totally understandable why they make that tradeoff, and quite possibly if SO relaxed strictness on that front I would be among those asking to reinstate it. It is, however, quite frustrating at times. So I think Quora is a nice alternative due to the more permissive policy there.

[Fire-Dragon-DoL]

Honestly this is the main problem. As a developer is common for me to ask about good books about a new topic I'm going to study (new programming language), but on SO such things are banned. You cannot ask an opinion on something you are working on. And since a lot of stuff are subjective, the more experienced you get, the less SO becomes useful. Hence resorting to Quora