I use Ilford Warmtone fibre a lot. Before Ilford (Harman) warmtone developer came out I used Neutol WA. This gives a hint of purple brown to the paper which becomes a stronger coolish purple brown in selenium. I find that Harman warmtone developer gives warmer tones, that become even warmer in selenium. I like to pull my prints before they get too warm, but this combination does give you options to suit your personal taste.
So I mostly use Harman warmtone developer with Ilford warmtone paper. But if I liked cool prints more, I would use Neutol WA more.

Alan Clark