Montblanc inks are pretty awesome. They flow well and have good properties. I haven't tried any of the permanent ones, though. The only thing that annoys me is when I come across an ink I like, and then find out it's a MB Limited Edition that's either no longer available or it's on Ebay for like $70.
Those two are exactly the ones I like best and wish for! It's okay though...I have a lot of ink and I'm sure there's analogs out there that are close to both of them, even if you don't get the same ink performance....it hasn't produced the Da Vinci or Honore de Balzac colors that I've been hunting for. Still, fantastic inks all around and very pen friendly.
The OP could correct me here, but there's Midnight Blue, which is an update to their older version and is iron gall, and then there's Permanent Blue, which I think is what's referenced in this thread.I have enough ink to get me through the next few lifetimes and I agree that Montblanc is good stuff (ogling 3 bottles of English Green)). I'm guessing that this colour is the updated version of their old Blue-Black and by extension is it iron gall?