Ahhh, In Flames.
I first got into them right after they had released their CLAYMAN album, although my first exposure to their work was WHORACLE, specifically the song "Jotun."  That I had not previously listened to bands with death metal vocals and that, in the short span of a few weeks, I owned all the releases of this band up to CLAYMAN was a real testament to how much I loved these guys.  The thing I liked most about these guys were how insanely catchy their riffs and leads were... I mean just listen to that main guitar riff in "Jotun."  Utterly unbelievable.
And then REROUTE TO REMAIN came out, the first In Flames album to be released since I had become a fan.  And I bought it, and I listened to it dozens of times.  It was easily my least favorite thing they had released at the time.  The main culprit?  The songs lost all of their hooks!  I struggled with that album greatly (I believe I wrote a review for it at 
www.metal-archives.com), and I thought there was some great stuff, but the material was wildly inconsistant, the songs maddeningly schizophrenic.  I haven't listened to it in ages, so maybe I would feel differently about it today, but it was a major letdown to me at the time, and I haven't listened to any of their material since, save for the odd single here and there, which never really impressed me greatly.  I remember reading an interview shortly after R2R where the band claimed the next album was going to be the heaviest yet... I don't come to In Flames for the heaviness, I come for the infectious and intricate melodies.  I'd imagine that the newer fanbase is much more interested in their new, apparently heavier, direction.
So I can't really have an opinion on whether older or newer In Flames is better, because I haven't heard their last few releases, so basically you read this entire post for nothing.  Sorry.  
