I had been using the beta version for a while now. For the last 2 weeks I have been using it as a remote head in my car using an old Nexus 4 phone. As a remote head it has been working great and the 4 inch phone screen is actually a bit larger than the Home Patrol.
Some things I did to improve my performance:
1) Do a clean system flash, do not go to Android 6, stay on 5.1 (6 won't want to connect to the AP because there won't be any internet access).
2) install Siren
3) Root the phone, remove or freeze as many system apps as possible with Titanium Backup. Freeze google play services but do not remove, in case you need to update siren in the future.
4) Put in airplane mode, then turn on wifi. This will put your battery drain down to almost nothing when you aren't using it (if you don't feel like turning it off).
When I did the above steps and let the phone just sit for a week, I only lost about 1-3% of battery a day.