I do. Although I don't do anything significant with it (as in reverse engineering or something similar)...
It's more of a "bonzai tree" experience for me, if that makes sense haha. I got myself a very (very) old box and have been hacking around with it, doing some assembly stuff. Nothing useful as I said, but I find it strangely relaxing. I go back every now and then to grow my "bonzai tree".
I think working with opcodes is most useful to actually understand what it is that is going on behind the scenes. There's so much of abstraction present nowadays that most high-level programming languages seem a bit like magic (take Ruby for example, some stuff it does is pretty fucking magical if you ask me haha). This is not specifically a bad thing, but I think it helps to understand what it is that is going behind all the abstraction. Assembly can help you understand that. Next time when writing commands (even the simple println "Hello World"), you will be thinking back to opcodes and shifting memory addresses, taking bytes and shifting them to the output device.
If you are interested in more, have a look at FASM (cant post link sorry, not enough posts) and go through all the tutorials. FASM (or flat assembly) is a pretty good, accessible assembly compiler with a large community.
Or you can ask me if you are interested in anything specific.
Cheers
