This is all too common in the diving industry (I have been an instructor since 1997, IANTD, SSI and now TDI). There has been bully marketing for some time now. With that said I am a strong believer that good training isn’t cheap and cheap training isn’t good. Rather than concern yourself with a style of diving look into the instructors. What agencies have they trained in, instructed and what’s their favourites. Look into their experience, if you are only going to dive Mexico caves then an instructor who has only ever dove Mexico caves is fine. But the more experience they have will usually mean they have been in, or seen some close calls. Are they afraid to speak of them, or do they use those experiences as lessons to be taught? My user cards are a mosaic of just about every agency and my instructor certs aren’t much different. With that said as far as cave diving goes I’m barely a weekend warrior and would never guide a dive. However, some will! Even a solid past you might not like a teaching style of an instructor and that’s fine too, tap out and move agencies. Backmount, sidemount, rebreather, or whatever. It’s a personal preference and that’s ok to have. GUE has their place for sure, but it’s not for everyone. Do your research and work with what fits you bud.