OK, here's what I did: I picked up a BatteryJunction TerraLUX TLE-110-S-MM Multi Mode 600 Lumen LED Upgrade for Streamlight SL20X Dimmable 110SMM. Fast shipping, well packed. I tried this out in the plastic cased SL20X I have. No problems with fit, except the reflector size is reduced somewhat by the plastic housing. Works like a champ. I ran it on high for an hour, just to see what happens. The plastic housing got pretty warm, and I think I'll replace the plastic lens with a borafloat one. Otherwise, no issues. The website says it is for the metal cased SL20X.
Next I put it in the Tigerlight. You have to pull the large rubber bushing under the lamp assembly, and cut it down. Just for messing around, I put a couple of packing peanuts under the drop-in just so it wouldn't rattle. It fits just fine, and you still have the dimmable function. I ran it on high for an hour, and judt a little heat buildup is noticeable. The Tigerlight comes with a glass lens, so no worries there.
