Well, here's my question, speaking as someone who's going to nab the HomePod at the earliest opportunity.
Is there any streaming system that isn't five-thumbed inept when it comes to classical? One where you're not constantly hopping from one random movement from one work to another random movement from some other work (and inevitably landing on Pachelbel's Canon in D and "Nachtmusik" every hour on the hour, as Spotify does)?
I tried Apple Music when it first came out, because I'm an optimist. I'm no longer an optimist when it comes to streaming services and classical. The basic problem is that track/album/artist isn't adequate to describe a classical track -- there's no obvious place to put the most important piece, the name of the composer, so everybody has their own ad hoc solution, and CDDB data is like a roulette wheel, and streaming services are great at telling you that you're listening to "First Movement, Allegro" without being able to tell you it's the first movement of *what* by *who*.
If you're not into classical, imagine that streaming services only knew about track and album, and there was no slot for artist, and you'll get a hint of what I'm up against.
Because I've got a reasonable collection with its metadata neurotically sanitized, the Apple ecosystem turns out to be a workable platform. (I even bought one of the 128GB iPods for use at work a few months ago when they cut the price, making me perhaps the last person in civilization to actually buy an iPod.)
To get into truly gory detail, I was also a pretty happy Apple Match customer, although their music identification software apparently leans very heavily on the first minute or so of a track, which means that it often failed on tracks that begin quietly, which works murder on a classical collection, and it meant a lot of uploading. But then Apple Music came along with its crap metadata and its inability to override or turn off their crap metadata, and that was the end of that. It simply demolished the option.
I'm going to order a HomePod as soon as I can, because it gives me a HomeKit hub, which I don't currently have, and as a quality AirPlay speaker, I can stream to it from my dedicated music server, controlled with the Remote application on my iPhone or iPad. This is a feasible approach, as long as (a) you spend eons editing your track metadata for consistency, and (b) you aren't logged into Apple Music and its ruinously inconsistent metadata.
Siri isn't a part of this choice at all, incidentally. I don't use it. It might be fun to try via HomePod, but I'm not expecting much luck.
