You descend at just about the stall speed. It's pretty close to the slowest the individual plane can go before losing lift. I believe the term for coming in with no lift, purely gliding, is called dead stick.
A Cessna 172 is worse, for comparison. I believe they are just 9:1. I guess it improves if you stop the prop entirely. I assume it is less drag.
best glide (converting altitude into the maximum distance) speed is quite a bit higher than the stall speed and found at the lift/drag max. minimum sink (converting altitude into the maximum time) is usually found about halfway between best glide speed and stall speed.
A Cessna 172 is worse, for comparison. I believe they are just 9:1. I guess it improves if you stop the prop entirely. I assume it is less drag.