Optical kerning as we know it from InDesign is based on an algorithm from Adobe. It was/is their own attempt to provide a proper kerning … well, sometimes it works, but IMHO most of the time it's producing horrible results. I for myself stick to the metrics option as it refers to the data from the kerning tables within the font-file. Manual kerning is used to make dedicated adjustments e.g. adjusting capitalized text (Versalausgleich) or (unfortunately) numbers. This option should be a standard for every serious typesetting software.
Conclusion for me: manual kerning and metric( font) kerning is a must have, optical kerning is an unnecessary feature.
Whereas optical alignment (nooo, not the kerning thingies!) is a must have for me as well! It was one of the typographic killer-features that came with InDesign back then (I remember a conversation with an old typesetter (Setzer) showing me young whelp back then that Gutenberg used it already in his bibles but it wasn't available in QuarkXpress or other typesetting software). Unfortunately these days not many people would recognize optical aligned text(columns). Anyway, if there is any chance to get this feature implemented I would be more than happy!
And for all of you, who only work on a computer: try to do all this things with real hot-metal types (Bleilettern), this is way much more painful but fun as well!