Fabian, the most important thing is the people and the culture. But to answer your traffic question, there is an old saying that is very true -- if you staff it, they will come. This is true when a facility is staffed regularly. The two biggest draws to attracting pilots are regular staffing and events. Pilots take notice when airports and airspace are staffed regularly. Even moreso when events are hosted and advertised. I'll give you an example: Just last night, Seattle held an event called TRACON Tuesdays (
https://forums.vatusa.net/index.php?topic=7568.0), featuring a number of smaller airports and airspaces, a good amount of training went on during a very, very busy event, and one student even got certified on position during the event. All of our facilities are encouraged to host such training events -- they are good for the students, the facilities, and the pilots. If any of the wonderful airports of the gorgeous islands are staffed regularly, and there are more and more events to promote the islands, you'll see more traffic.
One thing to consider that makes VATSIM a little different from our real world counterparts is that staffing levels play a much larger part in where pilots fly on VATSIM in the real world. In the real world, people fly where they need to fly for business, family, etc. On VATSIM, people like to fly to the "big airports", but a much larger draw for most folks is where they can regularly/consistently find good staffing levels and service.
Now, think about that aligning with your training. Even if the traffic levels in the islands right now are lower than some of the other booming major metropolitan areas, we have a simulator called "the Sweatbox" where targets are injected into the server for training purposes. So when undergoing training with a mentor or instructor, you're likely to be in the simulator. When you're working an airport/airspace solo to gain valuable solo experience, you'll have less online traffic to trip you up at first, yet it will build at a pace that you can safely and comfortably handle as you gain your experience and training, and as pilots see Hawaii lit up more often. Toby mentioned the challenge regarding flights from the mainland, but interisland traffic is a great opportunity to build volume. And hosting interisland training events to organically build more traffic within HCF is something that can bring more traffic more regularly. Again, a win-win for you, for the facility, and for the pilots.
All that said, what really makes this as a hobby is the people and the culture. They are the ones that care for you while you're learning, help bring you up to speed, crack jokes when you do something insanely funny and/or wrong, laugh also when you catch them doing something insanely funny and/or wrong, and laugh and commiserate when pilots make their gaffes, too. It's really about community, and feeling like it's a second home. Honolulu has just had a leadership change, and a strong, positive leader is currently in place, dedicated to doing everything he can to help grow his students and his facility. Not saying every other facility isn't, but it ties in very nicely, as you were asking where you can help the most. I have no doubt that if you join Honolulu today, you'll be received warmly, given gobs of attention, helped along the way, and will be successful.
Also, please know that as you grow in knowledge and certifications, you are also welcome to be a visiting controller at another facility. Once learning to unique nature of their airspace, policies, letters of agreement, etc., you can add to your arsenal of traffic, and more importantly experiences, by controlling other places as well, while still staying grounded in your home facility.
And if it doesn't pan out for you for any reason, there are 22 facilities in the United States, each with their own group of people, culture, training regimen, traffic levels, etc., so there are plenty of opportunities to explore something different.
I lead a Division with 22 facilities, over 1,300 controllers and students, and over 20,000 members. I'll never tell you which facility is best to join, because that's a decision only you can make, but I am happy to arm you with information and my perspectives and advice to help you make the best decision you can. In my opinion, pick a facility, make friends, see if you fit in, put in the time and effort required to be successful (it's considerable -- this is a challenging yet very rewarding hobby), and rest easy knowing you have a Plan B if you need it. And again, thank you for considering the needs of the Division -- looking for a facility that needs the help the most.
Hope this helps, best of luck, and best wishes for great holidays!
