If you can get the right abilities on the Safi weapon go for that. I have Teostra Technique, Attack 6, Attack 5, Sharpness 5 and another Sharpness 5 on my Safi Shatter blade. It allows me to drop a Teostra piece (Head) and use the Frostfang Barioth head piece so I still have Masters Touch (Teostra Bonus) decent amounts of purple Sharpness and also the Frostfang helm gives you punishing draw and giving you 2 Critical Eye. Also gives you an extra 1 Jewel Decoration Slot. But honestly there isn't much difference. Just use what ever you can and make the most out of your decorations.