Quote - Thanks guys for the opinions! I usually lower my bucket size too (I do believe that it takes long to render, it's a very detailed light) but unchecking the AO will, eventually, take away one of the most fantastic effects that the light gives... gonna give it a try anyway!

You are probably better off using AO on individual materials anyway. There is a great product in the store called "Occlusion Master", which is a Python script which lets you set AO on an object by material, or you can do it by hand in the material room. You don't need the overhead of having Firefly calculate the AO on items which won't benefit.