What gym do you want to go to? There are 2. There's the Aquatic Centre and then there's the Arena. The Aquatic Centre is more expensive, like $570 for a year or whatever, while the Arena is $350 a year. I just renewed my membership for another year, and I was told I would not have to pay the $55 as that comes into effect in July or something, but I'm not sure if that applies to first years.
The 2 centres are vastly different. The Aquatic Centre usually has more non students, but has more cardio equipment than the Arena. The Arena though has better weights facilities (The Aquatic Centre does have weights, but they're all cybex machines and squashed into the cardio room, however they are newer, and don't fall apart as often as the ones in the Arena haha...), however the machines time out after 20 minutes unless you're on a treadmill and you choose the long distance one - however beware, if you get on this machine and you walk instead of run, be prepared to be tortured and dismembered by others. And if someone catches you on it for less than 20 minutes, you will also die. But at the Aquatic Centre you are just asked to give up your machine after 20 minutes in peak times but it's not like anyone can really tell...
They also have different opening times, and the Arena doesn't open on Sundays or public holidays but you can use the Aquatic Centre for free on those days if you wish - other days you have to pay the casual fee. But sometimes they'll let you slide. It's also meant to be like $4 or something if you use the pool and you only have an Arena membership, but they never make me pay.
GF is pretty good - the classes get full though so it's best to make a booking beforehand and turn up early, or at least not late, or they'll assume you're not coming and give your place to someone who hasn't booked. Depending on what it is, such as say, BodyAttack, the room gets full and the last BodyAttack I did all the unco people kept banging into us.
GF is good, if you need guidance in how to do a good weights routine well then BodyPump would help you, but you shouldn't do more than 3 a week, and GF is great if you lack motivation. Also, when you do a GF you get a GF/gym (i think..) or GF/swim pass, so you can do the class then go for a swim. You should check the timetable in the pool though, as sometimes it's booked out for water polo - usually in the evenings.
If you don't care which gym you go to, I recommend you do a casual to both and see which one you like. If you're a super gym junkie you can get the executive pass which lets you into all of them.
The Aquatic Centre has better opening hours, and the Arena does get really, really full, sometimes there are lines to use some of the machines, and we just got new machines that are bigger than the old ones so there's slightly less machines than before - also the Sport Teams use the Arena to train, so at times you get whole teams coming in and taking up machines, but eventually you figure out what times who comes in and know when you can get what you want.
Ummm....I dunno what else to say...oh, if you want your fitness assessed, joining is also good, because you a free assessment every 6 weeks depending on the length of your membership - I'm in the top 93% CV fitness wise of the Arena, phwoar.
So that concludes my essay now...if you have anymore questions just ask me...I use these gyms 6 days a week, sometimes more than once a day, and have been for a long time now...so I should be able to answer whatever. And I'm friends with everyone who works at the gyms so I can ask them anything.
Oh but be warned, Ralphs Cafe is right across from the Arena, and around 10-12 the smell of their cooking drifts into the cardio room and can drive you completely insane if you're doing a long workout...