I thought about getting the rDock with my Solo-Mini (tried it for a day) but could not be doing with all the cables required for full functionality including RS232 (The promo pics never show the cables.)
As far I am concerned Arcam should have provided a one cable 'umbilical' system (for all signal & power & control) if used with their own Solo range or AV amps. (With the corresponding one connector power/control/signal socket on the Solo)
The whole point of a Solo system is having a minimalist, one-box solution with as few leads as possible (just mains + speaker cables). The rDock power lead + control cable + signal cables looks a mess.
Also, given that a decent quality RCA phono cable pair is usually quite 'stiff'/unbendy (more pronounced if using a short lead) it is difficult to keep an iPod dock upright because of the tension. (Chord Crimson may just be bendy enough.)