Yea that makes a difference, still it's much more than that I think.
Looking at the cubic grains Tri-X looks very different to HP5 to me for example.
I'm not familiar with Fomapan yet; actually the shot above is from my first roll.
It's also different to HP5, HP5 seems always more "gritty" to me.
Traditional cubic grain (Tri-X, HP5, Fomapan) vs modern Tubular grain (Delta, TMAX, Acros) I guess