Well, after much umming and arring I bought the Deros. It comes with a 125 and 150 head which you can flip between and the offer I got included the Systainer, hose and a few boxes of 150 discs.
The weight of the unit is very little different to the Ceros and doesn't have an external power supply which makes it far more versatile and orca tick to use. Variable speed is great and before I had the feature couldn't really work out why is was beneficial, I've found that if any dust does not get sucked up because the media is easy to sand, slowing the speed and hence the cutting rate allows completely dust free sanding. (There are times when hogging material off with a low grit is a big advantage such as filler etc.)
Overall impression, the best sander by a long way of any I have ever tried before. Expensive, (Festool price level) but in my opinion there isn't anything better on the market.