Recently, Pearll posted what are the strongest add pot for accessories, etc. I find it useful for anyone who is interested..
Best to worst :
8/8/6
8/+2/6
8/6/6
8/6/5
+2/6/6
8/5/5
+2/6/5
+2/5/5
I personally try not to keep any +att or +1 if possible but for value sake both are approximately 3% equivalent
Credits to Pearll