Just as an update, I did end up ordering the JBL kit. It took weeks to come, but I suspect the delay was because they've re-released all their CO2 kits with new names. Easy two now has the snappy title 'Proflora U402'! (God, can you imagine the brainstorming session that came up with that?)
Anyway, the kit is fantastic. Build quality is superb, reg is neat with huge easy to turn needle valve knob, solenoid runs off 12v (less electric - I think?), comes with UK plug, and very thin wire (easy to weave around cabinets), and the solenoid produces no heat or noise whatsoever - except a nice solid 'clunk' when it turns on or off.
It comes with a fairly ugly internal reactor, which looks like it would be very efficient, but I'm using an existing glass diffuser. If I had a sump (or perhaps a much larger tank) I would use the provided reactor. It's made of clear plastic. They also provide a non-return valve, bubble counter, drop checker, pipette, colour solution, flexible black CO2 tubing, and loads of JBL fertilisers (which I haven't looked at yet), and a pretty good instruction book. I'm not using the provided reactor, drop checker, or fertilisers, as I already had those in place from previous systems. Always nice to have some spares though. The plug incorporates the transformer, but is no wider than a normal UK plug. It is about 4cm tall, and will usually be sat on top of a timer.
So, in summary, it's certainly not the cheapest way to set up a CO2 system, especially if you already have some of the bits and bobs, but for a one-stop solution, it's pretty impressive. Everything is well designed and made, and little touches like including a pipette to fill the drop checker show great attention to detail. The only thing you need to add is a timer. The whole thing is beautifully displayed and packaged (for shop display) but I did think it could be packaged using less cardboard. However, it is ALL cardboard, so recyclable. Didn't check whether it was recycled cardboard.
That's the end of the mini review!
Best,
Mark