G'day Matt,

That completely depends on personal preference, the footprint is 270L x 265W cm, so something close to that size but bear in mind that because it has a round base, you'll need to be tent pegging through the mesh.
If you want additional length at the doorway so you have a verandah, just add the length you want there to the above dimensions.

G'day Suzi,

The power consumption of these lights is negligible, and the size power bank you go with depends on how many nights you'll be camping for, and if you will be intending to re-charge your power bank during the day at all.
Something like a 5,000mAh power pack should see you right for a couple of nights.

G'day John,

I've just tested this one out for you instore, and it fits no problem.

G'day Tina,

Yes, you should be able to fit this mattress. We've given it a go with the Coleman Queen Airbed and that fits well. Your mattress is 5cm longer and 5cm thicker, but we don't think that will cause any issues.

G'day Marko,

The Blackhole 4 Tent isn't really suited to use with stretchers as the sides of the tent curve up quite a bit, and the overall height is only 120cm at the centre. The Blackhole 4 Tent is designed for use with floor-based mattresses.

G'day Kerrin,

Yes, you can fit two of the Exped Megamat 10LXW mattresses into the Blackhole 4 Tent.

G'day Cook,

You should be able to fit Mattress 1 in the tent, but not both mattress 1 & 2. Have a look at this blog which should help. You can base the size on the Oztent Cicarar 3.0 4P

There is a vent situated at the top of the tent to the rear, Tony, but there is only one access point for the Speedy Blackhole tents. 

The size, set-up and dimensions are all pretty much the same as the old versions, Jana, the only upgrades were the blackened fabrics and the addition of a lighting system.