just tested the new firmware on the h520e rtk. 7 back to back flights done with 2 payloads and no payload. with no payload at the location I was at the h520 rtk stayed connected and I had no control and or connection issues to the controller for the flight controls themselves. with pay loads there may be indeed issues with the cameras firmware. e90x had lag in areas where it did not have any before and bit for frequent. the e30zx had some lag as well in flight but not as bad as the e90x. however on the sd card there was no lag on the video file. so the lag may be with the st16e video link. the e30zx issue of one picture and one video file as not came back and remains fixed from the last e30zx firmware update. firmware number that ends in 23 as a nasty bug for the e30zx.