Our latest meetup, Storm vs Spark face-off, was a big hit among Big Data engineers in New York. Slides from our meetup and from Hadoop User Group in Chicago presented on this page. I hope both of those presentations will help you make better choice for your use case and environment.
Apache storm vs. Spark Streaming
P. Taylor Goetz, Apache Storm Committer at Hortonworks
Yahoo compares Storm and Spark
Video from this talk.