Thanks to anyone who voted!
The results are in, if you're curious: http://blog.sematext.com/2015/09/30/log-shipping-poll-results/
Personally, I'm surprised we didn't see more people sending logs in JSON. Seems like 99% of Logstash users do that and according to http://blog.sematext.com/2014/10/06/top-5-most-popular-log-shippers/ Logstash was/is the most popular log shipping tool out there.
Somewhat related, if anyone's interested, this is happening today:
Monitoring * Alerting * Anomaly Detection * Centralized Log Management
Elasticsearch Consulting & Support * http://sematext.com/