In my experience they're not too good and are very unreliable.
I can back this up
Also, a word on using splitters: It's easier to use a splitter with a computer than using a merger with a phone, tablet or console and the headphones I have come with a splitter that's also an extension cord. It's not an issue to use a splitter unless you can't find one or it's a stupidly-proportioned splitter.
also the ones I use are HyperX Cloud Core I didn't say that earlier but I actually looked at the box now
