Hi CentralPA,
In the same ILD (keeping in mind that Dunlop ILD’s aren’t typically as accurate as Talalay ILD’s) … Dunlop will typically feel firmer and less lively than Talalay. While it’s not as “realistic” as personal experience … post #7 here has a little more and includes a video about the differences in “feel” between them.
It’s really a matter of personal preference. In my own case I prefer the “feel” of Talalay while my daughter (who is also tall and slim) prefers the feel and slightly less “lively” response of Dunlop.
As you also mentioned it can be very subjective because each person can “define” or perceive softness in different ways (see post #15 here).
Phoenix