Well, with refresh up and sanction u can have full time. Here I'll do the math for u:
Perdu 504 delay
Asumme 20% haste on gear(cause we're not all rich)
+ 20% marches
+10% hasso
+15% haste
Total: 65% haste
504-65%= 176.4/60 2.9 seconds per swing
Rune chopper 504 delay
25% haste on gear
20% marches
10% hasso
15% haste
Total: 70% haste
504-70%= 151/60= 2.5 seconds per swing
2.5/2.9= .86 100-86= +14% damage.
It's not quite at the level of haste I thoguht it was, but it will swing 14% more times and WS 14% more times than perdu GA. The base damage on perdu is a factor however it won't be a 14% damage increase. Anyone who knows the math for that can feel free to edit me.