Gushes (emphasis mine):

Sound! Euphonium: This has become the smash hit of the season for me and a strong contender for one of my shows of the year. It continues to be great in many ways; its collection of characters, its excellent directing, how willing it is to tell the story with small things and small gestures, and more. I'm not sure what the show is 'about' as such, which is one measure of (good) quality, but in part I've come to see it as an observation on what 'going for Nationals' really means for the people involved. In your typical sports show the narrative is basically all positive; here, we are seeing the cost spelled out, in strained relationships, crushed people, and so on.

Have I mentioned yet that this show is plain beautiful to look at? Because it is. The animation and visual appearance is lovely and the directing is top notch.

When I mentioned that Euphonium was essentially a sports show with girls, a few folks were sceptical, but that classification seems even more apt now.

UPDATE: Steven points out that Ani-nouto was on an extended break. Not exactly sure what's going on, but perhaps it's a rebound from Shirobako. Out here, a truly outstanding series like that often causes a lull, when everything simulcast or queued falls short in comparison. Initial D cast a pall like that previously and it took Yuyushki to restore the palate.

But I have a feeling, Euphonium would not be very welcome in any case. It's almost a Yamakan or Shinbo show, stylistically and story-wise. Too nasty. I know a lot of people fall for it (see CKS above). They feel that it's more real that way. Me though... To be sure, Euph is beautiful. But it's not what I want in my anime.

UPDATE LATER: Chris disagrees with the exact classification:

My view is that while Euphonium certainly has elements that also appear in sports shows, it is not one itself. A sports show like Ping Pong, Haikyuu!!, Yowamushi Pedal, or even Girls und Panzer strongly features the actual sport. Good characters and their stories are important, but in a normal sports show the overall story is in large part driven by the conflict inherent in the sports competition and actual 'games' feature prominently.

Sound! Euphonium's story is not structured like this. The actual band competition barely appears and there are none of the normal tropes of sports shows, like actual rival bands and rival performers in them; in fact we don't even see a competition performance from another band [...]