Seems a long time ago that i first posted about the Planex. Well, I bought one - with the dedicated vac. The apartment is long since finished and I've done another house with it since so I guess it has paid for itself. It's heavy and cumbersome at first but once you get used to it, works like a charm/Festool. One problem is with ceilings, that if the surface is really out, the vacuum effect doesn't work and your shoulder and arm muscles get a serious work out. Once you've got things reasonably smooth, you can regulate the suction so that it virtually holds the sander against the ceiling, making work much less tiring.
I did have a problem with the dedicated vacuum - it automatically clears the filters every thirty seconds, but after extensive use (I bought a second filter so that I could clean one with compressed air while using the other) it seemed that each time the filter cleaner process occurred suction was lost. After taking the thing apart - (I never knew you could have printed circuits in a vacuum cleaner) - turned out the electro-magnetically operated pistons which activated the filter cleaning syytem were sticking (too complicated for my liking). They now work fine after I cleaned them and lubricated them with silicone spray - I've no idea if that was a good idea but it works. Since then, when I've had just a small area to sand I've used the vacuum with a regular paper filter bag - thus keeping the main pleated filter clean. Don't know what caused the problem, but there was a fair amount of dust inside the motor - sheetrock/plasterboard/spackle dust does seem horribly fine.
I've not got any jobs on at the moment that recquire the Planex so its sitting idle in its jumbo systainer, but the dedicated vacuum is doing a good job trying to keep up with the Kapex.
As an aside, from looking at other European vacuum manufacturers i see that the Planex vacuum is not a Festool design. I don't know whether they make it under licence or get it made for them in their colours. Whilst it's OK, I prefer my CT 33 which is a real workhorse - just have to remember to change the bag as it can really pack them full.