It depends what you are carving.
When you get into the land of gouges there are more holding-styles-andgadgets than you imagine.
Unless you have full sized pieces in the round, (which I don't do) the normal bench is your friend.
Personally I try not to sit at work through preference, so carving lettering on large, flat boards can insult the back muscles whereas small pieces need to be lifted.
Many years ago, on a well-know auction site, someone was having difficulty unloading a really knackered and wormy Tiranti Scopas Chops - one of the good, pre-war ones with the brackets made of cast metal instead of the pressed steel you get nowadays. The wood was fit only for the fire, so I re-made this as an over-sized version and this, on top of my normal bench gets me up to a good carving height for most pieces that will fit in its jaws.
But, as I said it's down to preference, ingenuity and what you carve.