I'm thinking of purchasing a Platinum next and I cannot decide whether to go for the #3776 and the President. I'm just wondering if anyone had any experience of both pens to be able to offer a comparison. Whilst I can appreciate that one has the slip & seal and the other doesn't, I only tend to use washable inks, so it is not such a big deal for me. If anyone has had both, and could offer an opinion then I would be grateful. What's the difference between the 14k and 18k nib? I'll probably go for the medium, as I like the line on my other Platinum medium.