I have several test packs of paper brands, all sorts. Like you mentioned the Ilford Gold Fibre Silk is a very smooth 'perfect' paper with a very fine micro-grain. The paper is very good but is a little bit too perfect for my taste. Another very smooth fine detail paper is the Harman by Hahnemuhle Gloss Baryta (also in a warmtone version). This paper has more gloss than the Ilford, most definitely perfect for very fine detail. A very beautiful and well made paper, you can see it's quality. And although the surface is very slick, it still has more life than the Ilford for me, there is a very slight surface texture. Highly recommended.