As far as I'm aware, as it's normal system operation, the resulting landing distance is the normal when not using the reversers, see the performance tables.
Once the mains are planted, you can start the selection process for the reversers, whilst you are smoothly lowering the nose, then throttle the reversers at that time, that's very efficient use of the system.
BTW...the 737NG also has a backup system where if there is a fault preventing the EEC sensing of the engine anti-ice system
or flap landing positions, the engines will go into Approach Idle at 15,000 feet AMSL on the descent.
As far as an RTO is concerned, since the weight remains on the wheels throughout, the EEC keeps the engines at minimum ground idle (normal ground idle setting).
EW73
