Before T/d,our sops suggest to use Capture mode in descent page when on top of a 3 deg descent at 290kts.
Gives us a practical 1000ft min initially to avoid and Tcas RA in RVSM.
In Vnav it captures then the path.
However,in many airports speeds restrictions are cleared out and short cuts given..so I often use LVL Change once airspeed is set and established in descent to avoid disconfort to PAX.
Boeing recommends LVL Change then VS in the last 1000ft which will allow you a precise glide capture...avoiding unecessary increase of power in noise sensitive areas.
Speedbrakes are used primarly in Egypt and greece...mmhhhh...
Safe Flying,
M.85