I got one recently for KI and my MadCatz sticks. I'm very happy with it, especially since they were running a sale on it. You have to connect an Xbox One controller through the device initially to authenticate the controller, then you take out the Xbox controller and plug in the stick. It's a small hassle but works. The pad, however is essentially useless for that session, though as the convertor is essentially using that controller's ID to pass inputs from the stick. I'm honestly not sensitive to small lag, but I haven't felt anything noticeable.
On the PS4, it's real wonky. You can't do that because the PS4 authenticates every 8-10 min, so you need a PC that you plug the stick into, be running their program, and have the convertor connected to the PC with the DS4 kept plugged in. It works, but it's kind of a hassle.
For the Xbox One, it was totally worth if for me since they ran Black Friday half off sales, and I only play at home solo/online.
However, it might be best to wait it out a little longer, as they teased a new product to be announced this month, and it might eliminate needing a PC for the PS4. Chances are the authentication part won't go away, so you'll still be essetially down one pad while using it.
