There are plenty of Linux filesystem viewers
available for free (as in, read-only) and that's all I've ever needed. The things I do on either OS are so different as to be disparate, and I find little use for write access from one to the other (although Linux has had solid ntfs support for quite some time now). Anything I REALLY need to share, I just stick on a USB stick or in a shared folder on the NAS (running Samba, of course).
Nevertheless, native, transparent access to a Linux filesystem is an attractive idea.
Checking out Paragon's offering now, thanks for the tip.