I have recently been warming up to warmtone papers and have been playing around with Ilford WT, Foma WT and Oriental WT. I had never used a warmtone developer in the past so a few nights ago I purchased some Zonal pro HQ warm tone and my standard developer Dextol and chose one negative for a comparison across two developers and different papers. My goal was to settle on one WT paper and get to know it well. My regular paper(at the moment) is Arista edu (Foma). I printed each of the four different papers(test strips for each one) as close as I could with Dextol and Zonal pro HQ. I hung all eight prints in a row and evaluated both wet and then dry, and I was quite surprised at the results.

All warmtone papers gave a similar tone and the surprising part was I could not really tell the difference between Dextol or Zonal Pro HQ. If fact, I was probably convincing myself that one had to be warmer than the other.
The Arista edu was the coldest in Dextol as expected, but that paper with Zonal pro was definitely warmer and almost identical to the warmtone papers.
Oriental, and Foma WT gave a gritter print when compared with Ilford WT. So I am still not sure which I prefer.

So in summary, it didn't make any real difference(in my use) using Dextol or warmtone developer (at least this one) on a warmtone paper.

I would be interested in hearing other thoughts.