I played it briefly a couple of years ago. At the time, I thought that the complex battle system combined with the dated menu navigation made it difficult to get into. I was overwhelmed by its game design, but I'd like to give it another try someday. The story seemed intriguing, and I dug the music.
I've barely touched it, but already I can tell the navigation and combat is dated compared to SMT4, or Persona 4, or Etrian Odyssey 4. But I think that thanks to my experience playing those newer games, I might have a better understanding of what's going on in Soul Hackers than I might have had otherwise. I hope it will help me get into it.
I was thinking along those lines, too. Having a better understanding now of other Atlus-developed RPGs may just alleviate some of the challenges that I ran into playing Soul Hackers. It might not be as user-friendly as Shin Megami Tensei IV, but the shared gameplay mechanics allow some knowledge to translate between both games.