In my experience, a certain percentage of users will always complain about user interface changes, no matter how good they are. I have always believed in a pol

In my experience, a certain percentage of users will always complain about user interface changes, no matter how good they are. I have always believed in a policy of waiting ~2 weeks to let the changes "soak in", and gauge whether the complaints are just a knee jerk reaction by a small percentage, or is indeed indicative of a larger problem. This is also one of many reasons you find larger companies doing a "roll out" of a new UI change. It's a good way of gauging user reaction while only affecting a small random sample of your user base.