Here is a line from Alcestis' famous speech to her husband before she dies. From Euripides' Alcestis.
"Admetus, you see the things I suffer; and now before I die I mean to tell you what I wish."
Click on the above images to see the display of this line as I saw it in Firefox, with an undefined font. The first is precomposed and the second is decomposed. Both show vowels of uneven size and decomposed shows a lagging perispomeni.
Ἄδμηθ', ὁρᾷς γὰρ τἀμὰ πράγμαθ' ὡς ἔχει, λέξαι θέλω σοι πρὶν θανεῖν ἃ βούλομαι.
Ἄδμηθ', ὁρᾷς γὰρ τἀμὰ πράγμαθ' ὡς ἔχει, λέξαι θέλω σοι πρὶν θανεῖν ἃ βούλομαι
In the Greek text which I have posted here with a defined Tahoma font, the first is decomposed with combining diacritics, and the second is precomposed. In the preview window they look identical and correct.