Digital BW, The Print

I have several rolls that I have accumulated for development, pending
finding a developer that gives a good result.  I have tried Xtol with
no success beyond ei400.  Recently, someone (Steve Anchell)
recommended that I try Ilford's DD-X.  Has anyone done this, and found
times that work?  Other push developers with good results?

Here is the test I've devised to reach a time for an EI with a
particular developer:

I photographed a gray piece of fabric with a moderate texture at both
3 stop over exposuse and 3 stop under exposure (with the film rated at
1600).  I then cut a small piece, develop it at 20C for x minutes,
scan it, and am looking for a balance in the texture with the two
exposures.  Make sense?