I do think there is some benefit in the Padi classes. Compared to the tech level classes (which I am going through right now myself), they are a lot less detailed, especially on the skills side. However I believe you get out what you put into a class. I have a stack of Padi certs, and although some were probably not really necessary, I did get something from each of them to improve my diving.
In answer to your question i would recommend the Padi deep diver cert. For me that was my first introduction to deeper dives, and my first lessons in deploying a DSMB. I am glad I had this training then, and have been able to build on it and repeat over the past ten years while building my diving experience level. I would also recommend any class that you are interested in, as it will encourage you to dive more and to gain more experience, which ultimately, is what will make you a better diver overall.
Now going into tech, while it definitely wasn't necessary to take those classes, it certainly helped!
In answer to your question i would recommend the Padi deep diver cert. For me that was my first introduction to deeper dives, and my first lessons in deploying a DSMB. I am glad I had this training then, and have been able to build on it and repeat over the past ten years while building my diving experience level. I would also recommend any class that you are interested in, as it will encourage you to dive more and to gain more experience, which ultimately, is what will make you a better diver overall.
Now going into tech, while it definitely wasn't necessary to take those classes, it certainly helped!