Tom Duffy said:
. My real conclusion, that I've come to time and time again is, "why would anyone use tmax when they have txp available?"
your results may vary...
I haven't done the stepwedge yet--but I'll get to it sooner or later-- I went ahead and plunged right into a box of it for a job I'm printing at work. I shot over 350 4x5 negs (TMX and mostly Ilford ortho) on some 100-110 yr old photos, postcards and cyanotypes. I shot grayscales as well, and developed two ways. A normal run for a CI to get me into a grade 2, and push & pull runs as well. Now--the majority of these had to be cross polarized as well--so it's a real mix of contrasts.
I have found though, that when printed onto MGIV Deluxe, my highlights suffer in comparison to Poly IV. I really like using Polymax II for these types of negatives, and it would appear that Poly IV will be a pefect match. I have to make prints for this project--I'm going to start on the Poly IV and see how it does. Could be I wind up using both Poly IV and MGIV.
I haven't gotten to print any of our object studio shots. It will be interesting to see how the paper handles the mahogany furniture we shoot on white keys, being on the other end of the tonal scale--but for copywork, the highlights are often compressed--so this paper really shines for that.
In a perfect world, you can fine tune your negs for the material you print on--but that world doesn't exist with historical negatives. This is why I always liked having more than brand of paper on hand....polymaxII would always work for where MGIV failed and vice-versa.
I don't think I'll find one better than the other--just different. But, I can get a killer deal on Poly IV on contract....much cheaper than the ilford, and it gets delivered on time. YMMV as they say.