Same question.
I have experience only with R9 280X GPU's with Windows 7 -64
(16 GPU,s in four rig (15 running and one GPU disabled -- waiting new fans))
CGminer 3.7.2 - Kalroth edition, works like charm (of course if settings are ok)
yes I have tried also others and with this Kalroth stability and result is best without any hassle (after find all many settings optimized). Previously MC now waffle...
It can find here: http://k-dev.net/cgminer/
Version 2014-02-04 (Windows)
3.7.2 but in run it show 3.7.3
Also it is good to least read about "Lantis' optimized scrypt binaries".
Please repair eu server!
My ping is too long to useast
I run Kalroth, on both my rigs, didnt see much change in rates, but what i did get was better options on adjusting my cards, since i run some cards that need 2 threads and some that need 1 thread.