It's a muscle, so it's like muscle meat rather than like liver or something, but very fine grained... and a bit of chew.
It's beef flavored, but BEEFIER...
Honestly, if it was trimmed and cubed, they would probably be clueless.
Also, if you get heart with big hunks of white fat on it... trim that off and render it for tallow. The BEST tallow ever is on the heart.
I really like it sliced, trimmed a bit and seared rare, with a dippy egg for 'sauce'.