I don't often use the time filter. In the particular focus that I live in 80% of the time, most of my tasks are broken into pieces that are about 15 minutes and I usually don't make use of the "estimate" feature. However, 10% of my tasks take 1 hour or more. I can't do these on the train durring my 45 min commute. I would like a way to set the filter to allow ONLY tasks that have an estimated time of less than X AND tasks that are unestimated.