I am a member of AGO and I love it. Does it pay to be a member? Yes. We, my niece and I, love the member's lounge - good place to wind down after a two hour visit. I do not know about you but there is something hypnotic about museums, I feel dizzy after two hours. But in a good way :).
Except for major exhibitions, members' previews are relatively quieter. Previews allow you to appreciate the exhibitions before they open to the public AND you get to meet people who care and love arts ... not just tourists.
Oh I love tourists, just not in museums.
The collection is decent and adopts a "thematic" concept instead of periodical. For example, there is a section of women in power from different periods. I personally do not like the "thematic" concept as it makes it difficult for me to "study" arts. What it allows me to do though is to appreciate the piece devoid of any context when and why it was made.
But it's not sexy. There's also something sexy, oooh sexy, about entering a room with paintings from the same period.
Overall, your visit will be satisfactory.
Keep your camera because you won't be allowed to take pictures inside. I do not know the logic behind it considering that THE Moma and SFMOMA allow you to take pictures inside.
Why am I giving four? Customer experience is not as pleasant as other museums I've visited like Nasheer, MOMA or Guggenheim.
The guards are annoyingly hard core and seem to have taken a course on how to be a dick. I've been shouted at four times... only four times for standing too close to the pieces. They remind me of custom agents.
Scary.