While a higher arc and faster speed do make it easier to use, it also increases the capabilities of those that can use it effectively as well. As Sunderland said, the increased arc makes it a scary primary AND secondary weapon, it can be place on any slot and be a terror. I've seen it wreck shit off of the ass of a Galleon. The increase projectile speed means no amount of dodging is going to save you and makes lesmok a joke, you go burst for a humongous AoE that can disable whatever part of the ship you're facing. Mind you it also does respectable hull damage, so you can pair it with a gatling to make a terrifyingly efficient disable/kill machine. At least with the flak it was only ever effective alongside a gatling reducing its use to the Pyramidion and Junker and the odd Squid with a lot of balls.
The projectile speed in particular is worth mentioning again, that's NOT just lowering the skill floor for the weapon. No matter how accurate you are a gunner, there are shots you simply cannot land because the enemy ship moved while the projectile was in transit, they moved in a way you could not have predicted. It's why even Phoebe can't always win every match ever just by being on a Lumberjack. What this means for the Artemis is that what used to take a specific circumstance (the pilot has lined up a great shot) can now be done all the time without fail given moderate skill (disabling the enemy's engines while going fast laterally).
This is just for higher skilled players. In everyone else's hands, it's gone from horribly inaccurate to a reliable hitter. It's dangerously close to completely overtaking the Hwacha and it just utterly outclasses the flamethrower which already was having a hard time dealing with chemspray. A disabler/killer that turns fast, hits far, and does it all in record time? The only thing the flamethrower has going for it now over the Artemis is its ability to kill the balloon and that alone isn't enough to justify its use.
It's stepping on a lot of other weapon's toes at the moment. The flak did one thing and one thing only, kill the enemy when its armor is down. The Hwacha did one thing and that was disable, and maybe kill if a gatling came in (meaning you got roughly 3 guns' worth on the enemy at once). I don't think the artemis should be brought back entirely to where it was pre-patch and I'm very glad stuff other than flak/gatling is viable on light ships, but as effective as the weapon is right now this is what you'd expect out of a primary slot weapon, not what you'd get out of a backup slot.