Early Blu-rays used LPCM as their soundtracks as the mastering tools were very immature (and that's also why they used MPEG-2). Early Blu-rays were also single layer, which meant there was a severe space crunch - it was hard to put a 1080p movie and a 7.1 soundtrack without compromising the video to fit it all, which was why early Blu-Ray didn't go so well compared to alternatives. It's why a lot of early Blu-rays got reissued years later.
These days it doesn't matter as the tools are mature. You cannot compare two different movies as their mastering makes a whole pile of difference and it in no way reflects which method is better.