LTC is no good for my 7970, was not working stable atleast ~ month ago.
With a lot of tuning and frustration, I got my Gigabyte 7970 GHz (1100/1500MHz stock) to run stable-ish on Reaper v13r4 using AMD drivers 12.10, 12.9, and 12.11 beta 8.
The 12.11 is by far the most unstable though, and I still only make ~380-440KH/s.
However, with BTC GPU farms pointing at LTC because of the halving or because of the ASIC's, development on LTC miners will increase and a more stable version will be released.
However, it's still a crapshoot what you'll get.
For example, my game developer friend gets ~550KH/s on his HIS 7970 (Non-GHz), and the only difference was that I have 8gb of RAM to his 16gb, and he has a 3960X and I have a 2500K, and I was using 12.9 and he was using 12.11 Beta 4.
I upgraded and it became too unstable to run, yet he gets 110KH/s more than me at mostly the same settings.
Weird glitches like this will be fixed in time, especially with the HD8000 series (Code named Southern Islands, wasn't it?) coming out soon and a wave of Tahiti's hitting all-time low prices on retail chains and eBay.
Not to mention the vanilla 7970 is only $400, compared to the 7970 GHz's $450.
A quick BIOS flash and you just saved $50. And hell, the Gigabyte 7970 is as fast as the reference 7970 GHz.
