Great article! My two cents:
PNGyu should be included since the loseless compression is quite impressive
I agree tat ImageOptim is a compression beast… I am a little maniac since I usually do the following
All this with great results
PNGyu uses Pngquant internally. So the result should be comparable to ImageOptim in lossy mode.
It's unfortunate though that due to aggressive configuration some other tools get ahead of ImageOptim. But it's all at even greater cost of visual quality.
Yeah! Actually, for the PNGs, I still prefer Pngyu because in term of performances, it is a lot faster than ImageOptim.
Annyway, I am just a nerd… ImageOptim is the only tool you need