Ilford publishes the characteristic curves (density over rel. log exposure) in their technical data sheets (see www.ilford.com, under products). From that material it appears that the curve of the Delta 3200 is less linear than that for the Delta 100 and 400, and does not reach so far up. However, I don't know how it compares to Kodak products, because I have been using the Ilford stuff over a long time with excellent results, and it would take some time for me to get the same experience with other materials.(posted 9216 days ago)Two other things come to mind, however:
1) You are comparing a high-chem emulsion to conventional emulsions by visual inspection. A densitometer or a lab meter might reveal that the differences appear to the naked eye only.
2) Can you rule out underdevelopment of the Delta 3200? If it consistently lacks the high densities, that might be the reason. Again, using a densitometer (or a lab meter), this time to determine the gradient, might give an answer.