yes, you could defenitely experiment with "true ambience" but beware that it will take significantly longer rendertimes. You can use the ambient channel of your texture to adjust the brightness/intensity of the indirect light (the TA effect). higher ambient setting will increase the intensity, too high will make things unrealistic though probably, tweak around a little I'd say :) you could also use a radial or such for a fill light to shine some soft light on the shadowed area's that'll work faster then TA, but will also possibly create a different look then TA.

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