There's a guy here who is far more qualified to explain this than I am. I can only tell you what we expirence with ours. I also had some electric when I lived in Michigan. I couldn't rip that out fast enough. I don't remember whether it was more comfortable than what we have now or not. I only remember getting the electric bill and being ablolutly shocked. We had a forced air furnace put into that house the next winter and never had a heat bill come even close to the electric bill again. Incidenty, that house had crawl space under more than half of it. It wasn't much of a problem to the HVAC guys.
I'll grant you the zoning issue. We have thermostats in each room, which allows each room to be individually controlled. With hot water, you can get several zones, but it gets more expensive with each zone you add. As far as why hot water being more comfortable, I really can't explain why. I've had both, and I've heard from many who have had both. Everyone is in agreement that Hydronic is more comfortable. I agree that it doesn't make sense that one type of heat would radiate btu's any different than the other. I just know that this house never gets warm in the winter. I'm right now in sweats shoes and an insulated flannel shirt, and I'm less than comfortable.
I just sent Harold a message. I hope he'll stop in and give you some qualified advice.
Stop back in often, I'm sure there will be other opinions on this.