I played the inkbrush nouveau a lot in ranked before this weapon came out. This weapon is basically a better version of the inkbrush nouveau. The permabrush is the first inkbrush that is viable in competitive play. Splat bombs are powerful subs that can cover the brush at range. One of the best ways to use splat bombs with this weapon is to space with them so that the enemy is either walled out by your bomb or forced to get closer to you so you can splat them with your brush. If you can predict enemy movement and throw bombs accordingly, you'll get a ton of splats. The kraken with the inkbrush was a pretty good choice as well. The inkbrush charges a special really quickly and it has a low special depletion, so it almost always has a kraken. It can be used as a panic button, which is great because if an inkbrush uses it while attacking it's already in position to use it.
While it's possible for the inkbrush to splat in less than four hits, to do this you have to be swinging slowly. Each new swing will cancel out ink globs that the first swing would have had. If you are trying to swing fast, it will never be a two hit splat. Same goes for the octobrush. I think it's possible to get a two hit if you're swinging fast, but a one hit is certainly not possible.
The kit is very solid. I was hoping for a burst/zooka brush but this is pretty good as well. Just because the inkbrush is the main weapon doesn't make this a weak kit. If you play smart, you'll be able to catch a ton of players off guard and get lots of splats. Even the inkbrush nouveau can get results in solo queue if played right, but in the competitive scene the permabrush is the only viable one. And the inkbrush has a few niches that the octobrush doesn't. The permabrush is definitely better than the vanilla octobrush, and is on par with the octo nouveau. I really hope some competitive players pick up the weapon to use in tournaments.