Speedbrakes must be used if needed, we all agree in that, I'm sure. Only you have to think first if you really need them before using them.
I see speedbrakes as "energy dissipators". I will mot use them if I don't have excess energy, normally. Of course there are exceptions, like not too reasonable ATC requests or times where you need a very quick speed decrease without reducing you rate of descent.
Use of V/S at high altitude (a common practice even by those pilots who are afraid of it in other circumstances), can be very tricky. Mostly it is used in the bus when approachin crising level, this being at or above optimum, or near pmaximun, since the rates are so low and "oscillatory" that it seems better to keep a reasonable fixed rate at the expense of a few mach centesimals. But beware of doing this in a day where VMO and VAPROT are very close, specially after a "reach FL 380 before ZZZ". Don't let the airplane be at green dot, where the slide down the backside of the curve begins...