Fighting HSD vs. IMA is kind of like church members too busy fighting each other to get new converts.
As someone at another forum once said, each system has it's pros and cons. Ultimately, your power is still in that tank of gas. Honda seems to concentrate on an extremely efficient engine - Toyota with the recovery of kinetic energy. The HSD has the edge in the hills and urban driving - this comes from a Honda guy.
I'd like to rent a Prius next time Insight needs routine maintance. I don't pretend to know the HSD and won't pass judgement, but I love my Insight.
My critical remarks are reserved for Ford and esp. GM for being slow on hybrids and offering Employee Discounts on unappealing vehicles.