I find it therapeutic to "stick it up" hotels which have not lived up to my expectations so, yes, I give feedback of the negative variety. I'm not one to have petty or unrealistic expectations though so if I criticise then it's justified. Generally if I have an issue I like to have it addressed at the time of my stay where I can actually eyeball someone. That "someone" then has ownership of the problem as far as I am concerned and I expect them to resolve it to my satisfaction. I find that staff get uneasy about issues being raised in the presence of other guests so the reception desk is the ideal place to get a favourable response. Emails etc are way too easily ignored.