I have an AP, and I would say that maybe 25% of my trips are booked with AP discounts. I try to book bouncebacks when I can, and those have been pretty much equal to AP discounts lately. Sometimes they offer other packages or discounts with either a slightly better rate, or different validity dates, and sometimes it's the AP deal that's better. You really need to do the math every time to see what is the best rate.
So do the math for every option available for May and see which is the better rate. You can do a lot of it online, except for the AP part (since you don't have an AP to log in) but if you've already calculated the prices on any other available offers, you'll know right away if the AP rate is better.
I would recommend buying the AP for the admission value. If you buy it for the "perks" sooner or later you will be disappointed.