I was coming here to see if there was anything new and exciting, and I am a bit amused to be in exact agreement with Robert. I use Hahnemühle Photo Rag Baryta as my main photo black paper at my studio, as I think it is the best balance of quality, performance, archival characteristics and handling. Clients universally seem to like it, even if they do not choose it. The only downside I have with it is the now extreme cost, the short rolls and the strong curl at the end of the rolls. These are no worse than similar papers, in my experience.
I also really like Photo Rag Pearl for the reasons that Robert indicated, and I think Fine Art Baryta Satin has a lovely surface and I like the warm tone. I miss true warmtone papers, like Glossy Baryta Warmtone, but that line of paper was always a nightmare to handle...tons of headstrikes, extremely stiff off a roll, prone to print destroying scratches. But when it came out well, there was nothing that could closer match a darkroom print (at least an Ilford Multigrade IV fiber print).
I also use Photo Rag 308 as the standard matte paper, but I use German Etching as a textured, as it is not so stiff as most alpha cellulose papers, and I find that the price vs Museum Etching is worth it in my studio.
If you are looking for something different, I also really like the Awagami papers, though they bring a totally different aesthetic. While the Kozo papers are the most distinctive, I quite like Inbe thick white, which feels like an artist's sketch paper. It is thick enough to have some dimensional stability and not wrinkle from a higher ink load, but it feels fundamentally different and more organic than most Western papers. It cannot compete with them in areas like Dmax, however.
Meanwhile, I am looking into Canson. My experience has been mixed, in that I have found that the papers I have used of theirs (mostly baryta) have been too stiff and prone to head strikes, even with the platen gap maxed out and the suction on full. But I am going to give Platine Fiber Rag, as it seems to have very nice characteristics and is SO much cheaper than Hahnemuhle Photo Rag Baryta at this point...at least from my supplier. The difference is around 85GBP per 44" roll before VAT, not including the extra 2.5m of paper on the Canson.
What I really wish was available (or I would love to know about) would be a thinner, lighter GSM version of the best photo black papers. It is great that we can get Photo Rag 188, but there is no OBA free baryta or high quality photo black rag paper that is available in a lighter paper weight. For certain jobs the weight is helpful, but for others it is just paying for extra pulp. I would love to offer a lower cost option to my customers that would not be a plastic based RC paper with more questionable archival life. Furthermore, having a very thin photo black paper would offer really great opportunities for making artists books. I have made a few books now using the thin Awagami papers, and they look amazing, but it would be wonderful if it were possible to used a coated paper too. It would also solve issues like ink transfer, which is a problem with the matte papers (dark ink from one page will rub onto the facing page if there is a lot of paper movement).