Oh, there were definitely moments in the story that were lacking and, in the end, I think Ace Attorney is a superior series in terms of writing (and most else). However, I think I gave a pass to a lot of DR1's faults because of its novelty. It's a game that appeals to my tastes in all sorts of ways, and I think what the story nails shines brighter than what it fails at. Also, being an AA fan, the spin that DR has on investigations and the "courtroom" due to its setting were also engaging, and that lasted until the end.
I didn't really have a problem with its pacing, either. I can agree that, compared to Ace Attorney, resolving the murder mysteries was simpler because you're given essentially all of the tools and evidence you need before the trials, but that also gave it a different dynamic from Ace Attorney that I appreciated (since, in AA, moments when the protagonist is stuck are usually resolved through a new breakthrough rather than a new way of thinking). There were several twists that I didn't see coming, too.
Ha, and there was something appealing about the aggravating characters, in a weird way. They're a group that really doesn't get along with each other, and that raised the tension, suspicion and paranoia of the game's mood in appropriate ways