I picked up a Brook PS3/PS4 to Xbox One Super Converter today. I don't own an Xbox One. But I do own a PC and a pair of PS4 controllers, and after my latest batch of controller issues, I don't ever want to touch a third-party gamepad utility as long as I live.
Xbox controllers are pretty much the default on PC—a lot of new releases won't even work with anything else. Not many modern fighters handle generic gamepads in a sane way, and while emulating Xbox pads is possible, it needs tweaking depending on the game and your setup (read: it will fail when you least expect it and you will spend hours fixing it).
It might seem weird to use a converter for PC-compatible controllers, but it works. The Brook converter plays nice in every game I've tried, on both my DualShock 4 and my PS4 Hitbox. No config, no DLL overrides, no infighting virtual gamepads. If you don't have the patience to configure wrappers and emulators, this is your device.
Input lag is pretty common with adapters, but I didn't feel any noticeable delay while using the Super Converter. While I couldn't find any tests for this exact model, there are plenty of similar reports on YouTube and Shoryuken.com for every model of the Brook converters. It's impossible for any adapter to have zero latency, but the most rigorous test I've seen so far suggests less than one frame, which is about as good as it gets: there are larger differences between some fightstick PCBs.
What really surprised me was the Super Converter's wireless. I've tried using Bluetooth dongles for my DS4 on PC, but after going through three different models, they're all gathering dust; they'd drop my controller, lag out at the worst times, or just disconnect from the system entirely. The Brook converter's wireless worked first try, and it's smooth and responsive, even when the dongle's buried under my desk. I still wouldn't use it for fighting games (paranoia, maybe), but for a few rounds of Rocket League, it's pretty cozy.
The Super Converter has two extra features: a fairly standard turbo mode, which lets you set any number of buttons to auto-repeat, and control remapping for games that don't have rebindable controls. Both options are a little unwieldy at first—the status LED doesn't give you much information—but they're easy enough to remember after a few tries, and work pretty much exactly as expected.
Firmware upgrades are available on the Brook website. They're easy to install and pretty fault-tolerant, so if you somehow fuck up, it won't brick your adapter. There's also a Tournament Mode firmware available that disables remapping/turbo, but it's sort of a mess. You can still enter the settings modes, but they just silently fail, and there's no way to tell whether a converter is in Tournament Mode at a glance—pretty unfortunate for actual TOs. My unit shipped with Tournament Mode firmware, so if you have problems with the extra features, reflash the latest non-Tournament firmware and try again.
Last caveat: I've seen a handful of tournaments that require you to use extension cables with converters, since these things are a little heavy and could potentially damage cheap USB ports. If you're not worried about tournament rules, you can probably get away with skipping out on the extras, but cables are cheap: something basic should get the job done, no problem.
Verdict: The Xbox One Super Converter isn't just for Killer Instinct side events: it's also a convenient and simple way to use PS4 controllers/fightsticks on PC. It does its job and gets out of your way.