Quality Mode is for .15 of Factorio. It features faster mining, crafting, automating, and just a more usable variant of completely vanilla Factorio. Stack sizes are increased, fuels last a little longer, guns do a bit more damage, and just a little bit of a buff to everything. Power poles have better supply ranges allowing for much easier builds that take up less space than normal.

Patch Notes/Changelog:
2.7
After several iterations and bugfixes, Quality mode has been fully restored and works like it did in the past with all of its over-simplified glory
2.0
Transport Belts and Pipes now go much farther underground
Crafting speed for belts and tiles has been increased.
Overall Quality of Life changes continued (crafting times and speeds)

1.9-
Module Rework
Productivity modules Buffed (25, 50, 100% increase)
No limitations on productivity modules
Beacons accept P-Modules

1.8-
Nuclear revamp
Steam turbines should be fully functional again
Uranium processing now uses 100 uranium instead of 10 but yields the perfect 1:19 ratio every time. Just simplifies crafting procedure

Current Patch notes 1.7

Robotics moved to Red and Green science
Robots store more
Oil moved to Red and Green. Cracking is much more logical and oil is slightly simplified.

Player moves faster on all terrain. Even faster on pavements
Assembly machines craft twice, 5 times, and 10 times as fast as the player
Fuels are all significantly better and higher grade fuels increase train speeds
Power poles have larger supply areas
Mining speed for the player massively increased
Stack sizes increased across the board
Ammo does more damage and contains more bullets per clip
Modules are much more efficient.