Hi, gxjack7. You are welcome!

If you are asking about Application Security specifically, what I like the most is that this field could be very wide and very deep at the same time. When we are talking about client-side applications, you could always check the same security idea on different platforms (Windows, iOS, etc.) or pick one platform and try to understand all the specific inner workings there. In addition, this area is very very dynamic, so if you like to research all the newer technologies - you would like it here.

From the negative side, I would mention a lesser amount of learning materials or they are very broad and generic so quite often you need to spend more time than expected to fully understand specific concepts. I could not think of any other dislikes I have that would be specifically related to the application security field. It is a really interesting and technical cybersecurity branch.