I have a Zeppelein Air and purely based on the wireless connectivity, I can recommend it as I predomniantly use iTunes to listen to music in the entire home. With many apple products it is awesome! Ofcourse, I had the old Zeppelin and there is an observable improvement in Sound from Zeppelin Air when compared to Zeppelin.
I have not heard RCube so I can not offer any comparative opinion. Hope it helps
The rCube was one of our 2010 Award winners, and we're right in the middle of testing the new Zeppelin Air now. Our verdict on the Zeppelin will be published in the May issue of the magazine, on sale April 11th IIRC.
Having now listened to the Air and rCube at some extent I would personally put my own money into the B&W. The sound is bigger, more open, more musical and I know it's not the be all and end all but the Air does go louder. I also love the AirPlay functionality which in my mind is easier that having to put a dongle in your iPod/iPad to stream the music to it.
I am considering the Zeppelin Air or the rCube and I think I prefer the idea of Arcam's rWand and kleer technology. Air Play is very dependent upon your own wireless network and my iTouch has trouble picking up a strong signal.
I imagine the sound from a one box solution is going to be similar at this price and cannot really expect to be bettered.
For me what's important is being able to easily sit back with my iTouch and play music wirelessly. Therefore, any potential network or signal issues are a big turn-off. Toyed with the idea of a Sonos system but multi-room isn't a priority for me.
There's the wirless rDac as well but not so certain how that works. Perhaps it plugs directly into speakers or an integrated amp.
Went down to Audio T with a view to purchasing the R cube as I wanted the portability of the Arcam but more importantly was looking for the detail that the Arcam was known to produce. They set up the Arcam and Zeppelin Air in a listening room for me. I was there for over an hour switching my ipod between the two. The first difference you notice is the zeppelin's base, it is deep and powerfull without being overpowering. The Arcam did show a bit more detail on certain tracks but the zeppelin was impressing me more, it seemed to draw you into the songs and envelope you in the music, it was just a more enjoyable listening experience. I was trying different types of music hoping that the Arcam would impress me more as I really wanted the smaller dock and portability of the Arcam but after an hour I admitted defeat and went home with the Zeppelin as the listening experience was to enjoyable not too. One thing I would say in the Arcam's Defence was that Arcam say being a cube it sounds best placed in a corner where the sound can bounce of the walls which I wasn't able to do.