Haste/Haste II is a 3min base duration, not 5 minutes. Some people think its 5min and they're confused as to why it's only giving them a 10min haste with composure and gear as opposed to 12-15min.
With estoq cape/atrophy hands+1/estoq feet and composure:
Estoq Cape: 1.1x
Hands: 1.16x
Feet: 1.20x
Composure: 3.0x
Total bonus: 3.46x duration
Is it additive or multiplicative?
+Duration from gear is additive, +duration from composure is multiplicative, the +composure Empy bonus is counted as composure when cast on other people.
So
+10% Cape
+20% Empy +2 feet
+16% Hands
gives +46% from gear.
Empy Head / Body / Legs / Feet give a +35% when cast on others, otherwise +300% when cast on yourself.
Haste II is 180 seconds, so 180 * 1.46 * 3.0 = 786 seconds when cast on yourself for 13:06 duration. When cast on others it's 180 * 1.46 * 1.35 = 353 seconds for a 5:52 duration.