He's been my main since S8 and I've 675 kills with him. It took a while to learn how to play him.
I basically won a game solo with him yesterday. Round 5 with the only other squad hiding in a gas-trap filled bike shed on Olympus. It took one Knuckle Cluster to blow the bloody doors off then the shed was soon full of nades. The enemies came out into a hail of bullets ... game over.
His ult is only good for two things - dropping it on a third party fight or creating a barrier so you can res/heal yourself and your team. It's really dumb that TMs are undamaged by the ult, but Fuse is.
His nade ability is very good for getting camped teams out of settled positions. The final ring yesterday was at Estates in one game and I arc-starred an enemy squad off their building and onto the ground.
Nades are good sent quickly in pairs as they deploy via Fuse much quicker and directly. Pop one where an enemy is and one where you think they'll run to and you're in business.
The KC is good at getting people out from behind small rocks and bins. It's also good in early fights when enemies haven't yet shielded up. Okay, so the max damage is 35 but that can be a massive advantage in an early 1v1 scuffle. I've survived countless 1v1s unarmed v armed enemies early game that I wouldn't have done with Rev. I had a fun fight with another Fuse yday when he KCd me and then I KCd him. I won that one with a couple of punches.
The bad stuff? Sometimes the KC doesn't go where you want it to go. I've knocked myself with the KC at least three times.
In terms of ranking I'd put him above Rev but below all the usual suspects like Wraith, Bang, Gibby etc.