Here's my rather long winded review. Summary for those who don't want to read all of it: A great sounding speaker with very poorly implemented smart functions.
Sound - 100% agree with Ed's review, it's just amazing for a one-box system. I'm using it in a small room (12'x 8'x 8'), and it could really drive to party-level volumes in there. I think it would be loud enough for even very large domestic rooms.
I've got it right up against the back wall, and I find the bass to be solid, but never too much or too boomy. There is basic equalisation in the app (+/- 6dB for bass and treble) to fine tune for positioning, but I've not needed to use this yet.
Even the stereo separation is better than I expected. I listened to some John Coltrane in stereo and you could really tell the positioning of each player. It seems fairly good with more subtle stereo mixes too, certainly considering that is never going to be its forte.
Build - Good overall. Everything feels solid and the materials used are good. If I'm being picky, the gaps between the front and back of the unit aren't that even and there are a few small ripples in the plastic. Nothing too bad, but this is quite an expensive unit at full price.
General Use - I've had no issues at all with connecting my phone via Airplay and Bluetooth to play from my own music library and Spotify. There are no drop-outs, it's occasionally a bit laggy when changing tracks, but the room I've got it in is a bit of a dead-spot on my own network.
I've not actually got that much use for the B&W app as I use Spotify Connect and my own collection from my phone. The B&W app comes up with a 'now playing' section when using the latter, but it's easier to control it from the Apple Music (iTunes) app.
I like the LED light, but would like more adjustment in the app. It can be switched on/off and the brightness changed, but there is no way to change the fact that it stays on for 20 minutes after it has last played music or received an Alexa command. That makes it quite difficult to use in a dark bedroom at night after you've asked it to turn the main room light out!
As a result, I'll have to turn the LED off all the time, which is a shame as It's a nice feature.
Alexa integration - This is a real let down in it's current form. Hopefully they can improve this. My specific issues are:
1. It won't work as part of an Alexa group. It appears as an option when setting up a group, but the Zeppelin remains silent when all of the other speakers in the group are playing. The LED light doesn't even come on, so Alexa isn't communicating with it for some reason. This is a relatively big issue for me as it means I can never use the Zeppelin as part os a multi-room setup.
2. There is no way of controlling the volume of Alexa's voice, and it seems to be based on the last volume that music was played at. Yesterday, I was testing it at quite high volume n the afternoon and then asked it to turn a light off at 11pm to which it said 'OK' at a volume high enough to wake up everyone else in the house!
3. I can only use 'Alexa' as the wake word, rather than a choice as with all other Alexa devices.
4. There are sometimes random alerts - one the first two mornings I had it I was woken up by Alexa's voice saying 'Hello' at huge volume at around 6am! I'd not knowingly set that up, but seem to have defeated it with a factory reset.
5. It doesn't 'do' a lot of the things that other Alexa devices do - random questions are answered with 'Hmm, not sure' or 'I don't know that one' when all of my other Alexa units respond properly.
I use £10 Echo Flex units in some rooms and they have much better functionality than this speaker which has sold for up to £700. If the Zeppelin had line in, I'd certainly use an Echo Flex as the 'brains', and leave that functionality turned off on the Zeppelin itself.
Conclusion - This is an excellent speaker and starts to look like reasonable value at £529. I'd definitely say it's a better proposition for those using it to avoid having a full Hi-Fi system in a main listening room than for someone trying to use it as a true smart speaker, certainly in a multi-room set up.
The failed Alexa integration is a huge missed opportunity to those with the latter use cases. I'd like to have seen Google Home and Apple's Siri integrated as well. I don't use either of those systems extensively but I would do for the Zeppelin if they were better integrated than Alexa.
I can understand why B&W didn't offer any physical inputs, but I'd have liked to see one on a device where the sound quality is likely to outlast any current streaming technology built in - even if they had done it properly.