Blotbot:
Sorry for the long delay; I missed your post in January.
I use Manuscript pens often, and have little or no problem with the ink flow. Actually, I'm probably the wrong person to ask - I know very little about the mechanics of the pens - I just use them!
KrzysiekS,
I like Mitchell dip nibs but tend to use my fountain pens more often for convenience. I'm not familiar with the Sheaffer pens - I use Manuscript, Lamy or Rotring ArtPens most of the time. Actually, since starting this appraisal of Manuscript fountain pens, I've realised that I prefer the Lamy pens best of all for consistency and evenness of ink flow. The coloured ones with the interchangeable nibs are excellent (although they look a bit clunky with the huge clips) and the shape is designed to encourage the tripod or triangular handgrip which I would certainly advocate for beginners. Although these pens look large, they are surprising light and easy to handle without fatigue.