I was just in Bonaire at the end of May/beginning of June. Atlantis is definitely the place you want to ride at since it is offshore winds and the instructors there have boats to rescue you with in case something goes wrong.
Whether you'll find the wind gusty depends on what you're used to. It is not as gusty as Aruba, but I would never call the wind there 'smooth and steady', For me, it was gusty but I got used to it quickly and found it pretty manageable. I wouldn't say it was so bad that you are trying to figure out whether you want to rig for the lulls or the gusts but I gave my power/depower straps a workout. When we were there, the wind blew at about 20-30mph every day with a dip in speed during the middle of the day. We heard that it had been a very windy year so far and that other recent years had not been like that.
It is a much different feel than Aruba. No high rise hotels or resorts. All the lodging is more like boutique hotels. You pretty much have to rent a car, there are no hotels near the kite beach. We stayed at two different hotels and they were both wonderful.
Probably the only part of the trip that was not my favorite thing to have to do was walking through the coral to get out to the water. The coral rings the beach and they have a barrel on the beach marking the best entrance to use but I still managed to cut my feet up pretty good over the course of two weeks. I saw someone just launch from the beach into the water to skip the coral altogether - unfortunately I am not able to do that just yet.