When I find the time my next project is a variable speed fan built into the wall at the back of my lathe, and just to the right of the head stock. The intention is during the summer months while it is warm I will suck all the dust straight outside. (as long as 'er indoors ain't got her washing out)
It would also help to cool the workshop, of course it would chuck all the heat out in the winter, but IMO I reckon to get as much dust as possible out of the workshop is the best way forward. Of course you can revert to your other filter during the cold months.