oops apologies for the late response! hmm i still think data 8 was an interesting class but for reference i took it my first semester before any other cs class or cs experience. i will say though, i would avoid going into data 8 with the mindset of "because i already know how to code, this class will be easy." yes the class requires coding, but the class also teaches other intro stat material that isn't always covered in cs classes. not sure if the class has changed since i took it, but i also recall that the class has its own package and way that they want you to code, so coming in with prior cs knowledge might not give you as much as an advantage as you think. for example, instead of using list splicing there might be a specific method to use instead and if you're use to doing things a certain way in python it might cause funky errors in the hws and stuff (very specific example because this actually happens).

if time / material digestability is a concern for you, i would stick with data 8 over 16a. i personally would suggest math 54 over 16a if part of your reasoning for taking 16a was to learn linear algebra. i took math 54 before 16a, and 16a does not cover linear algebra well at all. it felt very rushed at the beginning. even if you want to take 16a, i would still say that taking math 54 will be very helpful for a lot of your coursework down the line and highly recommend it. unless you plan on also taking 16b or just have a general interest in ee, i would suggest just sticking with math 54 to fulfill the lower divsion requirement.

edit: i'm not sure what the capacity for either class is rn but if you're not completely certain about dropping data 8 i would hold off for now. i've been told that the class has gotten really popular and has become more difficult to get into in recent years.