I think these responses illustrate the inconsistencies. I, too, flew AC and LH back-to-back (YYC-FRA-RUH-FRA-YYC), with the first and last legs on AC and the other two on LH (on a 787-900 for AC, and a 340-300 and 330-300 for LH). From that experience, AC wins all around. The hard product is definitely better (especially better than the 340, which was a real disappointment), and the soft product comparable (service on AC was excellent, and the food passable). So, given a choice, I would pick AC.

However, from these other reports, it seems the experiences are inconsistent.