Though I did get the feature to work for about half an hour at one stage, I found a simple, yet self-defeating way to fix this problem: use the 3.5mm jack. One thing to note is streaming to the unit won't work while something is plugged into 3.5mm port -- Windows will tell you it's playing but there will be no sound. I had some success with the usually reliable Media:Connect app for iOS, but at one point even it stalled.
But whichever way you can find that works for you, there is no dismissing the sound; it makes products like the Libratone Zipp, though good, seem like toys in comparison. This is one of the most hi-fi "wi-fis" you will find for the price.
Of the three sound settings, it was a toss-up between the Bass Boost option and Natural. For rock music, Bass Boost was best and Natural seemed too thin while enhanced stereo sounded like it was being transmitted from out of a satellite dish with a sunken middle and exaggerated left and right. In Natural mode, the Aris had an intimate, detailed sound that was better suited to music from singer-songwriters or small ensembles.
Though the speaker is barely 15 inches across, it has one of the strongest stereo images of a speaker of this kind. We're not talking opera house spaciousness here, but voices sounded like they were coming out of the center of the speaker with a definite left and right channel audible from about 8 feet away. This is something you can't say of the, where all of the sound comes from over there...somewhere. The Aris provides more air around the instruments and voices and greater focus while the Zeppelin seems like it's throwing its voice: it doesn't draw you in the way the Aris does.
The Zeppelin's strength though is that it's designed to be listened to in the background and so from anywhere in the room, whereas move off-axis to the Aris and the sound closes in on itself, losing scale and immediacy.
Try something a little more complicated on the Aris though and it will try its best to keep up, for a while. The thud of John Stanier's toms at the beginning of Battles' "Atlas" were every bit the equal of the bass-heavy Zeppelin with plenty of punch, but once the other instruments piled in on top the bass response disappeared and the speaker instead tried to focus on the higher pitches of the "vocals." If you want something more consistent you should opt for a set of powered speakers such as the Audioengine 5+ speakers, which will give you an even greater stereo spread -- the drums come out of the left speaker in this instance -- and better bass response when things get busy.
Further dense music such as "Wasted Days" by Cloud Nothings sounded constrained when played though the Aris, and only when the bass and drums were playing together did it sound more convincing.
While we all wait for an official AirPlay module for the Aperion Aris, I'll have to say the Aris has the musical chops but is let down by its choice of instrument. However, it is one of the only wireless speakers you could even begin to pretend is an actual hi-fi system, and it is built to last. Its reliance on Windows is a sore point, and having to resort to a 3.5mm input defeats the purpose of buying this type of speaker in the first place. If the Airs were AirPlay-compatible by default, as well as DLNA-compatible, and could (magically) keep the same price, it would be a much more recommendable product.