Alan
I have one of these bought from Homebase. Their version (out of the box) came with a paper bag rather than a filter (which is available separately). It works well, the inlet port inside kinks round so you get a sort of cyclone effect.
When it comes to the filter I have to confess that I am a bit mean and constantly recycle mine by sticking it inside a plastic bag and then flicking the veins to release the dust etc. Then refitting it.
The filter fits onto the top cover which also has the motor attached. When you take the top cover off you will notice that there is a build-up of fine dust around the top (probably due to static...which is a bit of an issue with this machine but not overly so). What I tend to do is remove the filter and up-end the top cover over a bin or plastic bag to get rid of this fine dust. The downside is that, unless you have a second vac to clean the top cover etc before you refit things, then when you turn on your vac again, there is a huge puff of dust comes out the exhaust port. But....that could be down to me being mean with the filter. It does clog up very, very, very quickly if you are cutting a lot of MDF.
Would I buy it again solely for woodworking? Probably not..I'd take a longer look at other machines like the Trend perhaps.