So, I filled up a TWSBI 540 smoke with R&K Scabiosa and another with Diamine Bilberry. Both pens were "smoke" with Broad nibs, both pens had been writing identically before I filled with the newest colors. See this post for my musings on ink flow. When I went to find my sheets with Scabiosa, I found I had not written a full page, so I didn't have any scans to post. Having now used a full fill, I can tell you that I like the ink more today, than when I first used it. So, here are my thoughts and my torture test. http://sheismylawyer.com/She_Thinks_In_Ink/Inklings/slides/2013-Ink_524.jpg