Using Heatsticks and an Aluminum Pot

I've currently got a 30qt SS brew kettle that I use 2 1500 watt heat sticks with, doing all-grain. It's not large enough to contain a vigorous boil though unless I turn off one stick, so I'm looking at upgrading to a 40 or 60 qt aluminum kettle to stay on the affordable side of things.

I've read a lot on the sites about aluminum being much more efficient for heating the wort when using something like a propane burner, but what if I'm heating from the inside out? Think I'll be taking a hit on heating efficiency because an aluminum brew pot will work against me, dissipating the heat from the wort?

 

Wrap it in reflectex!

 

I highly doubt will have much, if any, impact on 2 sticks going full blast.