I have been experimenting with the G9 plus a Hoya R72 filter. I find the results quite good by shooting RAW, and then converting to B&W. I have uploaded some images into my website here:
http://www.paulobizarro.com/tema.asp?id=37G9 images are in the first page. I have previously used the G7 for IR too, but RAW allows for more post-processing flexibility.