Spark FW 701 or 900

[SpookieNZL]

Hi All, Not sure if already asked or posted on here. But I've been having a Few Issues Now with 900 Firmware. GPS Lost, ATTI Mode, Aircraft Disconnected etc. I've been on 900 since it been released but only now a few Weeks been getting Errors and Issues. Has anyone had similar Issues? Which Firmware Version is Stable? Should I Downgrade from 900 to 701? Interested in everyone's Opinions and Thoughts. If Downgrade from 900 will I also need to Re Firmware all Batteries too?