Really? You're missing out on a lot. I strongly suggest you go and pick one up... like, right now!
Right. The only other RPG I've played with a real-time combat system was Secret of Mana, which I liked, but not loved. As for Final Fantasy IV, don't be so down on yourself. It was my first game in the series (I played it last year and have yet to play another) and my first time through I had to stop playing because I was way too low-leveled and couldn't beat the the Four Fiends, and as you may know you can't leave that dungeon once you've entered it. I had to restart my entire game, and the second time through I destroyed them... but then there was Zeromus; easily the hardest final boss I've ever fought.