Autoworldnews.com posted an article about the Chevy Volt vs the Chevy Bolt. Now this isn't a competitive comparison but more of a looking at the differences. The verdict at the end is essentially ideal where they state that you choose what fits your needs. They aren't competitors but they compliment the range.
http://www.autoworldnews.com/articles/34206/20170311/battle-chevy-evs-chevrolet-volt-vs-bolt.htm
http://www.autoworldnews.com/articles/34206/20170311/battle-chevy-evs-chevrolet-volt-vs-bolt.htm
http://www.youtube.com/watch?time_continue=81&v=TX4P92Hqd3QThe Volt has more lateral cargo space behind its sloped hatchback. The EV has more vertical space like an SUV