I have been using TikZ in drawing scientific figures for almost 2 years, and like it very much. I can say several good things about TikZ: simple and natural syntax, good documentation, drawing in spirit of (La)TeX, easy tracing the last-move-to, etc.
I am impressive with the following comment:
While the previous systems (picture, epic, pstricks or metapost) focus on the how to draw, TikZ focuses more on the what to draw.
in https://en.wikibooks.org/wiki/LaTeX/PGF/TikZ but honestly I am not so clear what exactly it means. Is that TikZ's drawing philosophy?
I am all ears to see your opinion/explain! Thanks!