I already have the B+W but last night splurged out and ordered the Tiffen apeX. It arrives tomorrow from B&H. I will do my own testing of course, but was wondering if anyone has already used the Tiffen apeX and had some thoughts to share. Like virtually all other 10-stop filters, even raw photos shot with the B+W have a warm tint to them that seems attributable to IR transmission characteristics during very long exposures and I am hoping to get away from that. I'll be using both with Canon and Nikon cameras and these are the 77mm screw mount versions.