Thrust reverser efficiency at high speeds is quite dramatically demonstrated in the simulator (B737-300). With a runway length of 3657 metres sea level standard temp and 61 tonnes a rejected take off using both engines at V1 150 knots using manual speed brake, full reverse and no brakes results in an overun with the aircraft going off the end around 45 knots ground speed.
Ditto same weight etc but using speed brake, RTO autobrake and no reverse results in stopping around 400 metres from the end of the runway.
Ditto with slippery runway -RTO autobrake -manual speed brake and no reverse results in the aircrft gently sliding off the end of the runway around 40 knots. In other words proving what we all know about longer stopping distance if the runway is wet.
The final reject with slippery runway, full reverse and manual speed brake and RTO autobrake results in the aircraft stopping with about 300 metres to spare. The point being the stopping effect with full reverse really comes into its own on wet or slippery runways. The faster and earlier you apply reverse on a wet runway the better for stopping distance. Not a bad demonstration for those new to jet airliners although obvious to the more experienced.