Yup, both provided electrical and opto isolation.
The Opti Branch is best if you've got rack space available. The DMX Branch/4 is ideal if you're mobile and don't have racks. Place this in a convenient location to handle your splits.
For example, I use the Opto Branch/4. I send a split to behind me for the follow spot locations. I send another run to the stage for those lights and the foggers. Another run for the one tree, then another run that crosses the room to another tree and some lights in the middle.
If I had the DMX Branch/4, I'd toss that on the stage and split the stage lights and the foggers to speed up wiring. That would be in addition to the Opto Branch/4 still doing the exact same job.
Both are good, both are recommended. I prefer the Opto Branch/4 because it is rack mounted and I have one. Wouldn't mind having a DMX Branch/4 as well.
Want to save money? Get the DMX Branch/4 and give up nothing as far as features and functionality. Want a bit neater and have rack space? Then the Opto Branch/4 is the way to go. Win-win either way.