I tested some on my Multiclass Nalpazca monk/Streetfighter.
Got these results (used the same gear throughout the test):
Game version: v1.1.1.0064
Level 1 Alchemy 3
Duration 311.8 sec
Whiteleaf +13 Willl, 4.3 HP / 3 sec
Coral Snuff +18% Action Speed, +6.5 Deflection, +8 Reflex
Mouth Char -7% dmg taken, +18% dmg with weapons
Deadeye +8 accuracy, +18% interrupt on Hit
Level 20 Alchemy 3
Duration 368.5 sec
Whiteleaf +13 Willl, 5.1 HP / 3 sec
Coral Snuff +18% Action Speed, +6.5 Deflection, +8 Reflex
Mouth Char -7% dmg taken, +18% dmg with weapons
Deadeye +8 accuracy, +18% interrupt on Hit
Level 20 Alchemy 20
Duration 548.1 sec
Whiteleaf +32 Willl, 14.4 HP / 3 sec
Coral Snuff +37% Action Speed, +16 Deflection, +27 Reflex
Mouth Char -16% dmg taken, +37% dmg with weapons
Deadeye +27 accuracy, +37% interrupt on Hit
Reflection on results: Wow alchemy is awesome :D