Clear View Zoom and limitations

Recently I attended a wedding and I took a number of shots using the Clear Zoom feature via the kit lens and Nex F3. To my surprised the images were very good. I use the mag up to x2 magnifications, I am sure there are limitations to using this features, those who knows please contribute here.

It must be inferior to using the conventional zoom i.e 55-210mm lens, any views on this.