Now get out there and work through the new casino missions. However you decide to kit out your GTA Online casino Penthouse, you'll be living the high life in opulent surroundings. You can also kit out your suite with a variety of artwork pieces, which are accessed through the Interaction Menu > Penthouse Management > Place Decorations then choosing a room and the piece(s) you wish to purchase with chips before selecting a placement for them. Here, you can acquire casino chips in the same way you would from the Cashier (with the same restrictions), host a party for $20,000, order the Valet to deliver one of your vehicles from the garage, request a free bottle of champagne to add to your inventory, call in the Cleaning Service if your Penthouse needs a spruce up, order a limousine to take you to a set destination, or have a helicopter you own delivered to the rooftop helipad.
You do not need a to own a 'high end apartment' to join a heist as a crew member through an invite. You then have to wait for an invite from Lester to host each heist. This will give you a 'heist planning room'. The other key feature of owning a GTA Online casino Penthouse is being able to access Phone Services, available by picking up the telephone marked by an i on the minimap near the lift. According to the message you get from Lester you need a 'high end apartment'.