I appreciate honesty and straightforwardness some of the time. I like people to be honest when they need to be honest, but if their honest feelings are only going to hurt someone or cause tension I don't think there needs to be any honesty, or really any comment in the first place. Straightforwardness is good when you do need to communicate, when a topic that might cause tension nevertheless needs to be talked about (like when you and your housemates have different ideas about how to keep the kitchen clean) and not being clear and honest will only prolong the issue.
I guess I feel that you don't always need to comment on everything you think, but that when you do need to talk about something honesty is good. But I dunno. Lots of factors make it difficult to have one stance for me.