Yes I will do some unfiltred comparisons, though it blocks so much light pollution the sky would almost be completely white at a 10 min ISO 1600 exposure unfiltered. I use it to both increase contrast/detail of bright nebulae and to greatly increase the amount of very faint nebulae that can be seen like that on the outskirts of the lagoon nebula, and the Helix Nebula. The filter may not be as effective on Galaxies as the faint one in the Helix that is seen on an unfiltered one is visible
Filtered version
http://www.users.on.net/~josiah/baader/helixbaader.jpg
Unfiltered
http://www.users.on.net/~josiah/temp/helix45min.jpg (This needed much longer exposures at a lower ISO to try and get the detail, 3 x 15 min at ISO 400 as opposed to 1 x 10 and 1 x 15 ISO 1600 fir the filtered shot)
Scott