HoD was made by the same team behind SotN. Seriously, check the credits.
I mean I like HoD, but I wouldn't recommend it to a person starting out or anything. The deal with the Castle wasn't to be like the inverted castle (PoR toes that line far more closely), but to be more like Silent Hill. You have an evil world and an even more evil world, and what you do in Castle A (like smash a breakable wall in the Skeleton Cave A) will open a solid wall in Skeleton Cave B. Plus some areas like aforementioned Skeleton Cave will have different layouts. And box puzzles (hgngnghg). But constantly running back and forth will confuse a lot of less committed people and it's certainly the most divisive of all the Metroidvanias, CotM was far more accessible.
But yeah, I'd still Dawn of Sorrow would be the best bet if you're looking for the SotN experience. The castle is gigantic, the difficulty is juuuust right, the boss battles are very memorable and superior to the ones in SotN (topped by OoE and ReBirth, though), and the graphics still hold up very well 10 years later. The soul system is kind of wonky as Flame already explained, but I found that a lot of souls are effective enough as it is without upgrading them. The weapon system does stink, though, it was done much much much better in Curse of Darkness.
The music is also good but ironically I found that Masahiko Kimura's contributions were actually superior to Yamane's part of the soundtrack.