It's like this. Flashlight technology has advanced to include the driver circuitry and the battery technology. The Stinger LED is the replacement for your SL-20X and the Strion LED is sort of a replacement for the Stinger LED. My brother is still using his SL-20X as his duty light and his Stinger incandescent for backup in my town on patrol. When I talk to him about it he keeps on talking about hitting something with it lol. As a C.O., I cannot use my light as a weapon. At least, I'm not allowed to bring large lights downrange.
If you want a club, use your SL-20X. If you want a flashlight, you really need to go with the Stinger LED (the aluminum model, it's nice, don't get the fast charger get the regular piggyback charger) or the Strion LED or some other current technology light.
I don't think you can have both in a current generation light. You are a victim of technological advancement. Carry a nightstick IMO.