Our 1 v 1 damage isn't that bad at all. However, I will have you know that it is far from OP. Even with the reboot rebalancing that we got, the range of our octopunch still isn't something we can boast about.
If I were to choose a shade or bucc for bossing, shade would probably be my go to (even though I abhor the class). In my opinion, shades are much more agile and fluid when it comes to bosses like magnus.
Don't get me wrong, I love buccs, but we are far from the best when it comes to 1 on 1.
Buccaneers are not an effective class; I love mine, it's fun, but it's not effective. Your team utility late-game is poor(Few classes NEED Speed Infusion over Decent Speed Infusion), a lot of skills contradict each other or general game mechanics(Such as Typhoon Crush making you want to cube Physical Defense Ignore, but it's useless 40% of the time, but you need it 60% of the time...), their mobbing isn't that great in comparison to other classes, skills are luck based and not even THAT strong when they DO work well, etc...
Meanwhile, Shade brings fantastic party support in the form of binds, more reliable durability due to their regeneration mechanics, safer bossing due to longer range and disengage, more reliability in terms of buffs(They don't have many, unlike Buccaneers, so less re-casting and vulnerability to being dispelled or dying at fights), etc... they're just flat out superior bosses, who also happen to use pretty much all of the same equips and main stat, so if you're looking for efficiency they're the better choice.
But I always recommend playing for what YOU find fun, otherwise you'll probably quit; if you find good damage and high-end bossing fun, you may enjoy Shades over Buccaneers, but if you hate how Shade plays it's a bad decision regardless.