Battery. Also have the Hasty Sling Tanks has…amazingly better off hand shooting stability and fast to useI agree that the the ghost ring does block out more than open sights. An RMR does seem to be the best compromise between a scope and iron sights. I've been practicing at 50-75 yards, so 25 yards should be a snap. I suspect an RMR would make thing even easier.
To the guys who use the RMR, do you use the battery operated, or the fiber optic style? I've looked at both and prefer the battery myself.