People overcomplicate MATZ - I operate from inside one...
1. It's not controlled airspace. But treat it as if it were - unless they say you can't go inside, in which case it's up to you if you do so anyway. But tell them. (See 3.)
2. They will ask you to fly on QFE. Humour them.
3. It's a busy place with (usually) lots of fast pointy things. See 1.
4. The boundaries thereof are often not in GPS databases, so be prepared to use a map for a change. (They may ask you to report MATZ boundary depending on whether you are receiving a radar service or not.)
Tim