A long time ago i thought they were the same but then I realized that I mislabeled a bottle and I was in fact comparing hc-110 to hc-110.
This being said, they are very similar developers, of course. But I remember one time when I was struck at how good looking my HP5 negatives were, when developed in ilfotec-hc. So much that I went and purchased 2 bottles (and that’s when Ilfotec-HC was 55$ While hc-110 was twice cheaper at 28$). I now dedicate ilfotec-hc to ilford films and especially HP5.