This update includes the following:
- newest gregtech-5
- WarpDrive recipes fixes so you don't need GregTech HV tier to go in space
- WarpDrive fixes for the Transporter
- ArsMagica2 crash with Arcane guardian bosses
- modpack crashing on start when updating from 1.6.4 (AM2 was seeing OptiFine ghosts of the past)

Server has been updated to boost network bandwidth on slow and far connections (notably Europe/Asia players). Chunk-loading should be notably faster for them now.