Hard to say really since the idea of the Battlecruiser was an exercise in compromise, I think the Kaiserliche Marine had better Battlecruisers than the Royal Navy, the Lion class was probably our best Battlecruiser and even then she had problems because of our bad handling of explosive propellant.
But the Moltke and Seyditz classes of the KLM were probably superior ships, in my opinion at least.
Steve will probably have better data, he's got a lot of good material on the subject.
