I think the biggest annoyance by far is iTunes Connect. It's an odd beast. It's awkwardly separate from the rest of developer centre, and have this bizarre req

I think the biggest annoyance by far is iTunes Connect. It's an odd beast. It's awkwardly separate from the rest of developer centre, and have this bizarre requirement that you use a separate Apple ID for each iTC organisation, so you end up with one primary Apple ID tied to all developer programs and separate Apple IDs for each iTC account.