Sure, Logic for iPad is far more capable than GB but it is still pretty crippled compared to Logic for Mac simply because it lacks AU support. Yes, it supports AUv3 but just managing different plugin formats across 2 platforms is a deal-killer for me (and many/most others - I'd guess). Who has projects with ZERO 3rd-party content?
Oh well. Gotta start somewhere, sometime. Here's hoping cross-platform equivalency improves over time.