[Samsung Galaxy S 5 Unified Development] sylvisj:
Alright, so - time for more feedback collected.

My phone is a G900T. Due to the delays in unofficial nightlies, I've been running the official nightlies since 1/18. I believe my last post on the subject was just an update indicating 1/18 nightly was working with Ktoonsez' kernels, specifically his January 5th release.

Since then, I've run the January 20th, January 22nd, and January 23rd nightlies with the same January 5th build of Ktoonsez' kernel with decent success. They'd all had better bluetooth stability (my use case is Spotify) than the January 5th unofficial nightly at the cost of the camera not working great. Bluetooth audio streaming is far more important than the camera for my usage so I've stuck with official nightlies.

I've finally checked back in and saw the January 20th unofficial nightly and gave it a try - dirty flashing from the 23rd official to the 20th unofficial consistently resulted in getting stuck at the boot animation. I was able to resolve it by dirty flashing back to the 23rd official.

Attempting to go from the 23rd official to the 20th official to the 20th unofficial also failed.

So, I'm back to the 23rd official. I've used this opportunity to update to the latest Ktoonsez kernel, January 25th, and this combo is working pretty well for bluetooth. I had been encountering minor stuttering which seemed to be due to CPU load during cores being onlined/offlined; whatever the reason, the January 25th kernel is definitely smoother. It's not perfect, but it's pretty close.

In going from the January 5th kernel to January 25th, I've noticed KTMonitor showing more cores online far more often, with my GPU actually finally downclocking from 465mhz to 200mhz. It seems like the newer kernel build has greatly improved in onlining/offlining cores and adjusting clock rates, which coincides with my theory and observations on the bluetooth streaming audio stutter.

I'd imagine this translates to different battery life as well... CPU clocking/onlining is more aggressive but GPU clocking is less aggressive, so it might end up being a wash. Time will tell. I'll be doing a full drain, charge, and drain over the next couple days to get a rough idea on whether or not my battery life is different.

Bottom line:

* Doesn't seem like going between official and unofficial nightlies affected Bluetooth performance very much, but going from the older KToonsez kernel to the newer one made a world of difference

* Going from the older kernel to the newer one has affected CPU clocking / onlining (more aggressive) and GPU clocking (clocks lower during idle), so battery life and phone "smoothness" may be different

* Seems like the trip from unofficial nightlies to official nightlies is a one-way flash; keep this in mind if you want to try official nightlies.

---------- Post added at 02:36 AM ---------- Previous post was at 01:55 AM ----------

I just saw and grabbed the January 25th official nightly and am putting it through the paces with the January 25th Ktoonsez kernel.

One of the camera issues is fixed - just tested the "can only take one photo before Camera crashes" issue; fired off 10 back to back just to test it. It's still hosed for low-light photos, though.

Bluetooth audio streaming seems to be rock solid. I spent about 10 minutes bouncing between 3 chrome tabs (one of which is this thread), Clash of Clans, and Ingress, all of which would cause minor stutter previously, all with no stutter or hickup in playback. Phone temps are still good; CPU still being far more utilized than on the previous kernel. I'm increasingly convinced my bluetooth stutter was an artifact of the earlier kernel build.

I'm using the ktoonservativq governor and this is just buttery smooth. My S5 had not been this snappy, ever. Early CM12 was an improvement over touchwiz, but this... this is just excellent. I'm going to be going forward with a drain/charge/drain test on the January 25th nightly and the January 25th kernel.