Two things I have noticed since being on the DjeMBeY Slim M9 ROM are...
1. The Transition animation scale in Developer options which on all other ROMs kept reverting to 1x on reboot, now sticks at 0.5x. I don't know if this is a Samsung M9 fix or down to DjeMBeY.
2. The M9 modem, i9505XXUEMJ9, is giving me a better signal in all locations and times of day... even the Twilight Zone! I am always cautious about modems and most of the JB ones that I have tried have all been roughly in the same ball park. However, in the last 4 days I have noticed that in differing locations and times, I have been getting a better signal than usual. OK, its not a staggering difference, about -2dBm or -3dBm and 2asu or 3asu on average at my desk at home but every little bit helps! I should mention that that is on HSPA with the web browser open and using Network Signal Info
. No LTE/4G here in Miss Marple land.