Montblanc Meisterstück 149 Flex Nib Fountain Pen 119699:
A wonderful pen that works first time all the time. I guess that's what comes with a Montblanc. However, this particular pen is about the flex nib. I use fountain pens for sketching and flex nibs are ideal for expressive drawing.
I've used steel dip nibs, for example Zebra G nibs (totally brilliant but with only a two week life span). Vintage gold flex (super). Modern steel flex, for example Fountain Pen Revolution (pretty good for the price) and modern gold flex, for example the Aurora flex (not too bad but not great). The nib I have on my Montblanc isn't comparable to a vintage flex but is far more fun then most modern flex fountain pen nibs.
This nib puts out a good line each time of asking. The line variation is also great, from an extra fine to well above 1mm. Rail roading is noticeable but it occurs a lot less then in other modern flex pens.
My only real concern is the snap back! This is the time it takes for a flex nib to switch from when it's putting out a wide line to when it goes back to it's narrowest point. The snap back on my particular nib is lazy, it takes longer then some of the other nibs I've used. To counter this, I found that slowing down considerably alleviated the problem. However, that will reduce your normal expressiveness, and you'll need to adapt to another slower style of expression which means the finished product (in my case drawings) will be different but just as good.
Overall though, I really like this pen.