[Sony Xperia T, TL, TX, V] nreuge:
JB 4.3 for Xperia T is smoother and more performant than 4.1.2 but some system tweaks can still bring a more enhanced experience.

I present you XperiaTweaks v3.1

Features:

1- build.prop add-ons:

- dalvik tweaks

- dns tweaks

- 100% jpeg quality

- nfc off by default, statubar icon enabled when on

- dexopt-flags modified for compliancy with Z2 SystemUI & Home port

- other performance tweaks

2- Scripts :

- cleaner

- power management tweaks

- interactive governor with tweaked parameters

- deadline I/O scheduler

- low memory killer (lmk - minfree) improved for better multitasking

- sysctl tweaks

- remount optimized

- read_ahead optimized

- swap in cache partition (200 Mb, swapiness 60)

- darky zipalign

- databases optimized by sqlite3

Requirements:

- rooted

- Stock rom 4.3 /.205 (T/TX) or .210 (V) or custom rom based on stock 4.3 (for instance Ultimate PureXT or Rockers X)

- Busybox

- Smanager

Installation for stock rom 4.3 /.205&.210:

1- CWM Backup first

2- Flash XperiaTweaks_T.zip or XperiaTweaks_TX.zip or XperiaTweaks_V.zip via CWM depending on your device

3- Open SManager and select the scripts 1, 2, 3, 4, 5, 6 (& 7) in /system/etc/XperiaTweaks. Set them as "su" and "boot" and don't forget to save the configurations. For script 7 (sqlite), it's better to schedule it to run once a week rather than at each boot.

4- Reboot and enjoy :)

Update from v3.0: Skip step 3. SManager is operational again, you can update it via playstore.

Installation for custom rom based on stock 4.3:

1- CWM Backup first

2- Flash XperiaTweaks_Universal.zip via CWM

3- Open SManager and select the scripts 1, 2, 3, 4, 5, 6 (& 7) in /system/etc/XperiaTweaks. Set them as "su" and "boot" and don't forget to save the configurations. For script 7 (sqlite), it's better to schedule it to run once a week rather than at each boot.

4- Edit your build.prop:

Look for the lines:

ro.nfc.on.default=true
ro.nfc.icon.enable=false

and change them in this way:

ro.nfc.on.default=false
ro.nfc.icon.enable=true

Look for the line:

dalvik.vm.dexopt-flags=m=y

and change it in this way:

dalvik.vm.dexopt-flags=v=n,o=v,m=y

Look for the line:

af.resampler.quality=255

and change it in this way:

af.resampler.quality=4

And add the following lines at the end of the file:

########## XperiaTweaks v3.1 #########

ro.media.enc.jpeg.quality=100
ro.kernel.android.checkjni=0
ro.kernel.checkjni=0
ro.vold.umsdirtyratio=20
ro.fb.mode=1
ro.min.fling_velocity=8000
ro.max.fling_velocity=12000
ro.min_pointer_dur=8
net.dns1=8.8.8.8
net.dns2=8.8.4.4
debug.performance.tuning=1
debug.enabletr=true
debug.overlayui.enable=1
dalvik.vm.execution-mode=int:jit
dalvik.vm.checkjni=false
dalvik.vm.verify-bytecode=false
dalvik.vm.jmiopts=forcecopy
dalvik.vm.dexopt-data-only=1
dev.pm.dyn_samplingrate=1
persist.android.strictmode=0
persist.service.lgospd.enable=0
persist.service.pcsync.enable=0
hw3d.force=1
video.accelerate.hw=1
windowsmgr.max_events_per_sec=300

Save your build.prop and apply the correct permissions (rw-r--r--)

5- Reboot and enjoy :)

Advices :

- Do not install this mod if you have just installed 4.3. Use the rom without tweaks during few days to evaluate its potential, its performances and to detect its weaknesses,

- To my experience, launching scripts with SManager is much more reliable and versatile than with init.d,

- Don't judge this mod regarding the Antutu benchmark (that being said, you may get a score around 17300, which is good)

- Use your device with this mod during 1 or 2 weeks before to draw any conclusions.

Future updates of the mod : I no longer own the T (I'm now powered by Z2) but I'll keep this mod updated. Suggestions are welcome...

Updates :

- 21/05: v3.1: read_ahead increased to 2048 kb for better performances - audio resampler quality improved

- 27/04: Updated instruction about Smanager: the new version from the playstore does not work properly, install the attached version and do not update it!

- 15/04: Universal mod fixed

- 12/04: v3.0: mod updated for stock 4.3 / .205 (T/TX) and .210 (V) - One build.prop tweak added

- 01/04: v2.2: some build.prop tweaks added - Universal support for custom roms based on stock

- 20/03: v2.1: nfc off by default, nfc statubar icon enabled when on; dexopt-flags modified for compliancy with Z2 SystemUI & Home port

- 15/03: v2.0: mod updated for stock 4.3 / .199

- 04/03: v1.3: remount of /cache and /data partitions optimized

- 22/02: v1.2: some unnecessary lines removed from the scripts, some bugs fixed.

- 19/02: Xperia TX&V now supported

- 18/02: v1.1: missing zipalign added

Credits :

- Thanks to [MENTION=3110233]peetr_[/MENTION] , I've used some parts of the scripts of his hybrid rom

- Thanks to [MENTION=4282676]slaid480[/MENTION] for his sqlite3 and libncurse.so

- Thanks to [MENTION=2307984]delta-roh[/MENTION] for his script turbo boost triple swap that I have modified to perform well on Xperia T