I use the 128oz ice wand. I start with an ice bath then slowly penetrate the wort with my huge wand. I gently move it around clockwise and change directions intermittently. I usually come in 30-35 min. to 70o. This is the only technique I've used. When doing IPA's I use my wand to crush the hop leaf and release her oils. Everyone has been pleased with the final product. Just be carefull not to put your wand in if the wort is too hot or it will explode.
Seriously... I'm never getting an immersion chiller.