Kinda been out of the loop lately. Is a 2.6mh on 280x decent on this algo?
Negative. Look for Wolf's optimized kernels and that is what you will want to use. I found a complete package at crypto mining blog. Do a search and you should be able to find all of the optimized kernels for Sgminer.
That is the latest im using. I know he made a modified bin for x11 and x13 but have not seen one for x15.
Ahh found it on nicehash!
https://www.nicehash.com/?p=software#sgminer