It features a streamlined workflow, assisted opcode entry, draggable key-range and velocity splits-points, and more.

It supports all SFZ 1.0 opcodes (full 2.0 support coming soon) and directly exports to .sfz format.

I recommend using SFZ Designer in tandem with Plogue Sforzando for quick previewing. When you re-export your .sfz file all the changes are instantly applied in Sforzando. This is a feature in the player.