I like the ease of setup using the CloudFormation templates, and the ability to easily select the resources that make up our application(s) so that we can basically let Arpio take care of the hard part of cloning our resources into an alternate account and region & activating resources in the recovery environment.
I like the ability to test the recovery.
Failback is properly engineered as well. Review collected by and hosted on G2.com.
Certain niche AWS services may not be supported, but this can be solved for. AWS SES is a good example. You can manually setup this complicated service in your alt account and it'll be there when you need it. Review collected by and hosted on G2.com.