I loved the first third of D:OS but I got tired of the long, drawn-out battles after a while. It's just a matter of personal taste, but I really don't want to sink 45 minutes into one battle only to have it go wrong. The way I play is, if it looks like I'm losing, I'll reload rather than play another 30 minutes to watch my team fail completely. Because I know it's going to be another 30-45 minutes or more to replay the same battle again—at a minimum.
Apparently there's a huge audience for the system they made though.