If my preferred MOS isn't available and does not have many slots, should I wait for an opening or should I settle for another MOS?

Only accept the job you want to do. If the Army can't offer it, talk to the other services (including the Coasties - they are a great service!! but plenty fun to be had at their expense) That recruiter will help you more when you threaten to turn into a big waste of their time.
Their mission is on a number, not MOS.

It depends on your situation and how long you are prepared to wait. If you aren't in a rush to join the military, I would wait for the MOS you want. I would think that you would be happier in the long run.

John what did you end up doing? I'm in the same boat right now. Did you hold out? If so how long did you have to wait for a slot?

Are you fucking crazy

Um, you should definitely definitely definitely get the 15w slot. It’s aviation so it opens many many more doors for you. Life is “relatively “ cushier than other mos’s and you can still do high speed stuff if your into that ie. ranger , airborne soar etc. HMU if you have any questions...

Consider a closely related MOS if available. For example, a specialty maintaining drones or drone components such as engines or sensor systems.

Never settle for less than you want and deserve. The last thing you want is to regret compromising and settling for something less.

See if 15C is available. If it is, take it.

We just split MOS'. The split won't be official until Oct 1 but the Army shluld already be recruiting for both. 15W is Shadow amd 15C is Gray Eagle. If you want to watch buildings for hours on end, not be able to engage the enemy, and live in the field then you should pick Shadow. If you want to watch buildings for hours on end, have the ability to engage the enemy should the opportunity arise, and live on the airfield then pick Gray Eagle.There are three 15C classes run at a time with three shifts per class. Stick it out until the MOS YOU want is available, not the one your recruiter wants you to pick. They already have one. They doesn't care what job you pick, as long as you sign the contract with them as your recruiter.