I enjoyed it very much. Mike Cohn is an excellent speaker with plenty of industry experience and was able to make a two hour presentation (that started at 7:00 PM) fun.
His slides for this and other presentations at http://mountaingoatsoftware.com/presentations.
Here's some bullets summarizing what I took away:
- story points are for estimating stories in a product backlog
- they are numerically relevant, but intentionally “unitless”
- 3 key advantages (see page 14 of the slides):
- forces relative estimating
- focuses estimation of size (not duration)
- puts estimates in unites that can be added together
- (he says “time-based estimates are not additive”)
- sprint backlog tasks are estimated in hours
- velocity (calculated across sprints) is calculated in story points
- do not succumb to the temptation to use the task-hours from a sprint, because story points are quick estimates, and task-hours are much more carefully prepared
- planning poker is fun and effective
- it has been shown empirically to work (see pages 19-24)
- release planning can be easy
- (if one has a product backlog with estimates in story points, and has some data on past velocity)
I haven't made time to read Agile Estimating and Planning yet, but User Stories Applied For Agile Software Development came in handy for a project at work.
You may also want to check out www.planningpoker.com.