I like rollers but don't know much about them, used a German one for some time but forget the name. A while ago I was looking at fountain pens, not as collecting objects but to actually write with them. I came across the Namiki Vanishing Point and never looked back. It's a fountain pen with a tip that recedes into the pen, just like a ball pen. No fiddling with the hood, never had any leaking, works with either cartridges or loose ink, and it looks nice enough - and at a bit over $100 very affordable. Also easy to just get different tips for it that you can switch out, but I just got two of them to write in black or blue.