I have one of these with a fine nib. The pen has a very solid feel to it, and the weight of the body is just right for me. With the cap on, it is a heavy thing, but the cap is not postable, so is not an issue when writing. The nib is a very smooth writer, and I have had no issues with it whatsoever.
I have one and find it to be a wet writer. As a result, my medium nib laid down a wider line that I liked so I ground it to a cursive italic and adjusted the nib to be a touch drier. As beginish said, it is a solid feeling pen with nice weight.
I have the 300 and I agree with the previous comments. Nice solid feel about it. With the medium nib, never fails to start up after sitting for a few days. Have used it with Noodlers and Diamine inks, no problems.
I have this in a fine point, and it works great for me. As the others said, it is nice and solid. The cap is postable; you have to push it down until it "clicks". I don't post, since ti makes the pen feel unbalanced (at least to me), but YMMV.
I own this pen and like the look of it quite a bit. I would agree that the pen definitely is postable, but it's nearly as off balance as a TWSBI 540 in my opinion when it is posted.
If posting is a priority, a friend of mine has a Sheaffer 100 which is nearly the same pen but with better balance. The nib as I understand it is exactly the same, and the look to me is pretty similar. The nib is a really high quality nib for the price of the 100 (or even the 300).