Therm-IX FOOT WARMER SYSTEM

[midwif]

I just bought this on Tramdock for $80 (>$200 list price) in anticipation of new boots. Or maybe a gift for a deserving skier.
I currently have the Hotronic system which has lasted, though the older batteries don't last a full day of skiing/cold weather.
Any thoughts on this system? Anyone have experience with it?
I can always return it if its thumbs down.