Fussing with pens, ink and various types of paper is a great way for writers to procrastinate. Fountain pens need refilling, flushing, flossing and the dedicated can go for nib tuning and other such delaying tactics. Having said that, watching ink flow onto a white page is a delight in itself - but the paper, and the ink have to be right. Today, especially in the US, paper quality is low and fountain pen unfriendly. Okay, there's a perverse pleasure in filling out form where the ink feathers so much that company sends it back to you and asks you to use a ball-point. The correct response is, "Send me the form on a decent piece of paper and I'll fill it in again."
Above are some of my writing toys: fountain pens, ink, nibs, and notebooks. I rotate use of three or four pens, and for the most part, keep colours in certain pens.
I have used half a dozen Waterman pens over the years, ranging from student pens (available in Europe) to the better "Expert" range. Quite simply, I've never a bad Waterman nib, regardless of the price of the pen. I also regularly use a Monteverde Invicia Stealth Black, and a Lamy Safari (limited edition Petrol). As a gift for working at my agency for 25 years, I was presented a Montblanc Starwalker which takes putting ink on paper to a different level, and it almost never leaves the house!
Two other pens deserve mentioning as they are perfect for anyone who wants to start using a fountain pen, but doesn't want to spend a fortune. The Jinhao x450 and the Baoer 388 are both exceptional value and are very well made metal pens. The Jinhao takes a standard No. 6 nib that can be easily replaced should the one it comes with prove not to satisfy (a risk in this sub-$10.00 price range). The Goulet Pen Company sells nibs (its own Goulet nibs work very well in the Jinhao) and in Europe, nibs can be found on eBay. I have bought three Baoer 388 pens (only one for myself!) and their nibs have been very reliable and smooth. The main difference between the pens is that the Jinhao is quite a heavy, thick pen, weighing 43g empty, while the Baoer 388 is slimmer and weighs 21g. Both pens take standard international cartridges, though each will take a converter for bottle filling. Both of these are good everyday pens and cheap enough to carry anywhere.
I have never had any problems with leakages from any pen, even when flying.