I use a lot of audio production applications. I'm still on Mavericks, actually, because I haven't wanted to pay to upgrade perfectly fine software just so I could use a newer operating system. I have been receiving notices from software application vendors alerting me "Please strongly consider not upgrading to El Capitan yet, as there are compatibility issues that we need to work out."
So I'd guess the answer is -- it depends on what applications you want to continue using on your computer.
So far it seems OK. My /usr/local was preserved and restored automatically (mine was about 250 MB and the whole OS installation took about half an hour).
The split-screen view hasn't been fully-thought-through though. I would say almost everything I tried didn't do what I would have expected. There is a way for a window to end up on a space where the menu bar no longer has menus. There's even a mode where almost everything stops working: if the system decides only one of your windows supports splitting, it'll just sit there (even gestures won't work to reenter Mission Control) and you have to click to get out of it.
I wish they'd implemented a full tiled window manager. I'd really like to have at least 3 windows in the split view.
At the very least, an option to stack top and bottom instead of side by side would have been nice.
Seems like they want it to be congruent with how it works in iOS 9 on the iPad, so I don't hold out any hope. Maybe someone will figure out how to hack it.
So I tried it out last night. Overall things seem much more snappy though that is just a qualitative observation. Not much cosmetic changes. No WiFi issues no far!