I don't have much playtime on bloodhound but i always found his scan ability to be really wonky, the range is so short and sometimes it doesn't seem to pick up enemies even though they should be in range. Tbh just listening for footsteps seems more reliable, have more range and is not on a cooldown so the scan just seems kind of redundant to me.
I like his passive though, sadly it doesn't seem like many bloodhound players ping any of the tracks they come across. I honestly find that to be his strongest ability.
His ultimate has a lot of *. The activation time and the heavy breathing means you hear him practically across the map and know hes coming, mostly see Bloodhounds use it to run away lol.