Its hard to tell, but dungeons look a lot more fun when it comes to traversal and gameplay outside of combat. I'd definitely favor linear dungeons with mechanical variety, versus randomly generated dungeons only suited for grinding or trying out a persona.
In general, a reduced playtime with a lot less content, but the content that's there being great, is a very worthwhile tradeoff. A 30-40 hour long Persona game done differently sounds a lot more appealing than a very stylish rehash that lasts 50-70 hours.