Just thought I'd share this with you as I was surprised by the results.
I have an LBGE with no gasket. I recently purchase a 2nd LBGE. They are now in a table side by side.
I built the fire the same, I lit the lump the same, I cooked the same thing on both (Ribs BTW and they were great) and then shut them down the same way.
1) they reached temp about the same time
2) they maintained temp the same way (+ or - minor)
3) for the most part, the shut down was the same. The new egg with the gasket
dropped about 25 degrees faster during the shutdown process. (I figured that
the difference would have been significantly higher)
I'm not saying this is typical as not all eggs are built exactly the same, but this was my experience and I thought I'd share with you.