There are those who would say it's union or die. And some who would pass on the opportunity to join. From the little I know, I'll try to explain the advantages and disadvantages of being an Equity member, and from there I think the advantages and disadvantages of being a non-Union actor will become clear.
An Equity member has the advantage, first and most obviously, of the support of a union: contracts termed by AEA that producers must negotiate with actors. They include a base salary, health care, worker's comp, and appropriate working condition. Thus, the actor is protected. It's not that every Non-Eq theater pays crap, overworks their actors, or wouldn't provide worker's comp, It's just that some do and wouldn't, and that's enough. In Kentucky, I worked for a non-Union theater that required their actors to rehearse 12 hour days for 42 days straight (no day off), with a show tagged on to the end of the day for more than half that time. While the producer of that theater is a good man, whom I like very much, an Equity theater would never allow such a schedule, and that's why you'll rarely (if ever?) find an Equity theater that produces three shows in rotating rep over the span of 2 and a half months.
Another advantage of being an Equity member is the manageable audition process. Right now, as a non-Union actor, I spend half, and sometimes all, of my day waiting to be seen, because Equity members receive priority. And rightly so. I wouldn't mind so much being able to have a day job, and sign up for an audition time. That sounds heavenly.
And third, for the most part, and I say this timidly and with hesitation, many Equity productions are better quality productions. Some will disagree with me, but in my experience, this is true. (Let me insert here that I know many non-Union theaters across the U.S. that put on outstanding productions, but as a whole, this is what I see.) It's mostly because there's more money in Equity productions, as well as a more experienced team: from producer, to director, to stage manager, design, crew, and cast. All Broadway shows are Equity shows. An actor cannot be on Broadway and be non-Union. Off-Broadway...maybe. Off-off-Broadway, sure.
Disadvantages to being Equity: Well, there's the dues. You gotta pay. There's an initial fee plus a yearly smaller fee, and then working dues, which are a small percentage of each paycheck. There's the fact that once you're Equity, you cannot, or at least shouldn't, perform in a non-Union house. Doing so puts you at risk of losing membership.
Truthfully, there are quite a few disgruntled Equity members in the city these days. They say that non-Union jobs are taking jobs away from them. One example is the touring circuit. Once a Broadway show has been up and running for a certain amount of time, it goes out on tour. Used to be that these tours would all be Equity tours. Now, many are being taken out on tour by non-Union touring companies. Not all, but many. Why? It costs less. And less rules, I'm sure, has something to do with it. But primarily, it costs less. So, consequently, jobs that were previously given to Union actors are given to non-Union actors. Some theaters are also doing an Equity/non-Equity thing, where they hire Equity principals and a non-Union chorus. In many cases, this is how non-Union members earn points toward Equity. And then, there are the infamous reality shows, who hire whoever they want, who cares, as long as it makes good T.V. And non-Union members somehow end up making better T.V.
There are also those who caution an actor of becoming Equity too soon in one's career. They say that once you become Equity you're in a league with the big boys. You're up against the big names, the celebrities, the favorites, the experienced and well-known. Whether that's a disadvantage or just a fact, I don't know. I'd say it depends on the actor and what their path holds. It's hard to say. Non-union actors have gotten big roles in the non-Union houses and are afraid of not working again for a long time if they unionize. And sometimes that happens. But it all depends on one's goals, and if the actor is OK with playing big roles in the non-Union houses, or if they live in a city that holds a lot of non-Union theaters, then by all means, save your money and don't pay the dues. But if you want to work in New York City, and if, dare we say, you want to work on Broadway, well, then, take the plunge. Dive in. It doesn't get any easier. Just go for it!
That's what I know in a nutshell. I don't know much. I'm still learning, and I'm sure there's much more to learn from a producer's side of things, but this is how it looks from where I sit. You can probably see my opinion on the whole thing. I'm all for being an Equity member. I'm ready. But one thing's for sure. I'll read a lot less as an Equity member. I've never had so much time to read in my entire life, and that's not such a bad thing. But reading books, unfortunately, doesn't pay bills. And bills must be paid. The goal is to get them paid by doing shows here in New York City. That's the goal.