I’m currently enrolled in Level 3. So far it’s a great program–much like WSET’s wine courses (which was my introduction to them), it is a really solid foundation for spirits knowledge. I think that, since spirits are a bit more of a squishy subject than wine–with fewer laws and regulations hemming in production (not to mention the fact that distillation is a far more complex and choice-driven process than winemaking, with many more possible style outcomes)–the course is a bit more flexible/open in its conclusions than I remember the wine course being. I think this is a good thing.
It does seem like WSET has an understanding that spirits education cannot and should not be formalized as much as wine education has been, and I think that’s important. Plenty of roads are left untravelled in the course, it more serves as a jumping-off point for personal study in your area(s) of interest.
All that being said, my education is being paid for by a generous employer, which made my decision to take it much less fraught. If money is a concern, I’d say that you would be equally well-served and probably $1000 richer by just buying a copy of the Oxford Companion instead, and devoting a couple months of deep-study to that. 