Good review. I have listened to the Q3, S3 and S5 in the same room, and I share most of the observations. I would only add that the midrange is very very nice. It is for me the part of the speaker which stands out.
I completely agree with his thoughts on difference between ported and sealed bass. I lived for 20 years with ported designs (Cabasse, Triangle, Infinity IRS, Usher, Wilson...), but once I switched to a sealed system (EA MM3), it was impossible for me to switch back to ported. Ported bass gives a pleasing sound, impressive... but now I always hear the lack of linearity of ported bass, which smears the mid range transparency, and decreases definition of the bass itself.
Among the 3 speakers above, my choice is still the Q3 (I listen nearly exclusively to acoustic music: jazz, classical, voices). Less tolerance to bad sources, but more definition and transparency. And even cleaner and more transparent bass than the S series.
Between the S3 and S5, it is really a question of budget and room size. Their sound is very similar. In a good size room, the S5 does a better job at filling the room. It has more impact in the bass, which is quite normal with 10" drivers giving 60% more membrane surface... If I would listen to a lot of electronic music or rock, I would take the S5 - but both are excellent speakers.