Work great. Check YouTube for the hacks on the fuel cell and on the pads. They work and will save $$
I tried the fuel cell hack. There is an orifice you have to drill out in order to fill it quickly. I did this to 4 fuel cells and three out of the four valves did not leak afterwards. Not a bad ratio. I have refiled the modified ones a couple of times.
BUT...
That orifice seems to be needed. You can light the thermocell and all appears normal, but if you watch closely, the brand new pad will smoke a little more right at first and will turn white and then discolor a in about half the time that it takes a new cell to do. I am taking this to mean that the Thermocell is burning hotter than it should, producing a stronger, but shorter liked affect.
I noticed ill effects on the thermocell itself. The outside case does not feel dangerously hot. The only concern I have is that it might get hot enough to weaken the the plastic cell...that might get exciting.