I am talking about the question based on asking for advice in choosing one of x tools.
Reason behind this is, users intend to ask questions for finding a tool that will help them do their work. But comparison questions are quite deeper than that situation since the user already know something about two (or three) tools and asking for a comparison between these tools, expecting a detailed answer comparing the pros and cons of them.
Looking through this perspective, this kind of questions look more open to argument than questions asking a (generally any) tool that will help.
So, is it on-topic to ask comparison questions?
