I know what ya mean, the rendertimes are a pain! But there's still an art to it. It's a case of trying to find the fastest rendering solution to fit your needs. In this case TA worked faster for me then IBL and with better looking results!

Generaly I preview premium effects at 4rpp. Then I render only little parts of the scene to tweak specific things. Then finally pick out the noisiest parts of your 4rpp render, and check out how much rpp they need to look smooth enough to satisfy your needs and use the resulting settings for your final render.

(_/)
(='.'=)
(")(")This is Bunny. Copy and paste bunny into your signature to help him gain world domination.