[T-Mobile Samsung Galaxy S II SGH-T989] NoSpamDan:
Changelog:

NOTE: I don't have time to maintain this list, but will try to post notable fixes and/or updates in the announcement posts for new builds.

Some of these features are added by myself and may or may not continue to show up in the builds. Slim has started the weekly builds, but don't expect those builds to have features that aren't merged yet, like some of the below ones!

Slim-hercules-5.1.1.alpha.0.1-UNOFFICIAL-20150510-0238.zip

MD5: 9b5c79359586ea68337024dfb5ad103d

Fix mobile data issue(s)

Possible lag/wake from sleep improvements

Quick Settings tile customizations

Latest Slim commits...

Slim-hercules-5.1.1.alpha.0.1-UNOFFICIAL-20150427-1622.zip

MD5: 73b1f63585132cd9b2061a600f678459

Fixed Phone app FC

Display overlay CAF fixes

Mobile data may still have issues. WIP

Slim-hercules-5.1.1.alpha.0.1-UNOFFICIAL-20150424-0353.zip

MD5: 30ca89829189ed9f948557ed78addc89

Removed default DPI

Added low memory adjustment

v5.1.1 updates across the board

Slim-hercules-5.0.2.alpha.1.0.3-UNOFFICIAL-20150331-2040.zip

MD5: ef628d09cb118009294d5ffefed1d9bf

Torch/Flashlight tile is working

Low memory optimizations

Latest Slim WIP commits from RobbieL811

Slim-hercules-5.0.2.alpha.1.0.3-UNOFFICIAL-20150322-1213.zip

MD5: 9513ab23aebf5a686f88a2d2b474e097

New features like Blacklist, expandable volume panel, and SlimCenter (not fully functional to inform of updates yet).

Basic BLN support in the kernel. Enable/disable it in Settings > Sound & notification > Notification > Notification light

Should be a noticeable improvement in the occasional lag, but there seems to be a general bug related to this that affects many devices. With this device, it's more noticeable due to lower resources in general than newer devices have.

Default DPI is now set to the native device default of 240, but you can change this to several preset values in Settings > Display > LCD density.

Slim-hercules-5.0.2.alpha.1.0-UNOFFICIAL-20150312-1621.zip

MD5: 96e9564d849e5417853a3345c3e505df

Updated WiFi, camera and display vendor blobs.

Wifi: removed sockets implementation.

Lagginess should be improved, if not gone...

Slim-hercules-5.0.2.alpha.1.0-UNOFFICIAL-20150305-0253.zip

MD5: 2f5b21897d8cb6e1e716d1dfd6d370de

Power-off charging is fixed, along with animated images and even % display during power-off charge. So if your phone dies, you can charge it back up without issue!

BLN (Button Light Notificaiton) support, and it can be disabled if you want in the Settings menu! (Sorry no per-app control right now.) Thanks to [MENTION=4779996]gimmeitorilltell[/MENTION]!

Slim-hercules-5.0.2.alpha.1.0-UNOFFICIAL-20150228-2000.zip

MD5: e107b39affb47a364ab5f580689edef9

Kernel fix for keypad null pointer.

Fix for first install WiFi HAL soft reboots.

Slim-hercules-5.0.2.alpha.1.0-UNOFFICIAL-20150226-1411.zip

MD5: 207f2fca07b5aa31406bf56c4a94c328

Added power menu customization

Added SlimCenter

More Quick Settings updates, including a Reboot tile

Many other updates

Slim-hercules-5.0.2.alpha.1.0-UNOFFICIAL-20150222-0335.zip

MD5: 2c3cae9ada78381c94a6841f1f7d2591

Added Slim's new hardware key rebinding

MMS updates and fixes

USB Charging

Updated Quick Settings tile customization

Show each app name being optimized during boot

Slim-hercules-5.0.2.alpha.1.0-UNOFFICIAL-20150221-0808.zip

MD5: b3f8e7e88b05f879e3e11abea67ce9f0

Potential soft reboots fixed!

Fix for possible NFC bug.

Slim-hercules-5.0.2.alpha.1.0-UNOFFICIAL-20150219-1911.zip

MD5: a1969a9858e72cadbebf32533b6eebf1

Quick Settings tiles customization (Settings > Interface > Quick settings). Note: there still may be bugs...

Battery icon customization (Settings > Interface > Status bar > Battery icon options)

DPI changer (Settings > Display > LCD density)

Cursory RRO Theme suport. Slim is currently not implementing CM's theme engine. RRO is better in many ways... If you don't know what RRO Themes are or how to use them, check it out here: RRO Themes. (RRO Layers screen shots are in Post #3.)

Audio policy tweaked some more - Please test various audio/video scenarios.

Ringtones may not appear until after a reboot.

Various other updates and code clean-up

Slim-hercules-5.0.2.alpha.0.91-UNOFFICIAL-20150215-0300.zip

MD5: 98957c31680a17beea5b4e55b7f6bc1d

Mobile data and MMS are working now! Thanks to [MENTION=4800121]Sultanxda[/MENTION] for pointing me in the right direction!

Camera API updates and bug fixes (no 1080p yet though)

Torch

Audio policy cleaned up

Media codecs cleaned up

MTP transfer mode is selected by default

Removed unused libaudioamp config

Re-enabled qcom aac encoder

Removed call volume steps prop overrides

Removed PowerHAL

Various other updates and code clean-up