Same gun all the time. The best back up to your EDC in the event your primary carry should ever go down is a duplicate of it.
Consistency is a good thing especially when it comes to a defensive firearm. Train with what you carry and carry what you train with. It's better to master one gun than be a jack of all guns but the master of none.
YMMV but it's what's worked best for me.
When we do hit it we hit it out of the park and send it over to China as quickly as possible to cheapen it and sell it.