Shortwave's been a solid antidote to my inbox. The AI stuff like Smart Summary is neat, but the actual value of Shortwave comes from reinforcing the GTD habits. Clean design, plenty of keyboard shortcuts, and a concrete vision.
But it's not perfect - I sometimes feel railroaded by the Smart Labels. It tends to be a bit over-eager in labeling since a lot of the logic is based on the email sender.
TLDR: if the GTD workflow appeals to you, Shortwave is probably a good bet.