I bought the Rutlands model a few weeks ago. It's very quiet (certainly compared to running any tool in the shop). The Record model looks to have a slightly better design with an additional clip to hold in the external filter.
Whilst I'm going to keep the filters, I'm planning on mounting it such that it ejects the air through a vent out of my workshop. My 'shop is so open/full of holes that it'll easily draw in air from the other, erm, "ventilation points", and it'll make the issue of filtration efficiency somewhat moot.
That said, I've been running it on medium for a couple of hours after leaving the workshop whenever I've kicked up a bit of dust, and I do feel it's helped (less of a dust "smell" when I return the next morning, if that makes sense). I'm not noticing much/any visible dust on the filter (contrary to some other reviews I've seen) but then I do try to capture/extract most dust at source.
So far, I'm pretty happy with it.
EDIT: Some info in this thread lead me to
http://tmcwoodworks.blogspot.co.uk/2015 ... .html#more, so I decided to take a look to see the PCB in my Rutlands unit. Unfortunately the case does seem quite different, and despite getting a fair bit of it apart it looks as though some parts of the plastic panels clip into one another, and would have required more brute-force-and-ignorance to get apart than I was willing to attempt this evening.