-1
It's certainly a direct upgrade from stock, but think about why it's good: you can outrun the boss.
So, this should warrant a nerf for the Gunboats as well, because similarly, soldiers can jump away from a boss indefinitely. But with the BFB the boss, 1v1, can at least get the passive rage charge to catch the scout. For the jumping crit soldier, it's a different story.
Scout certainly has the other pick, F'aN, that has a similar method of keeping away from the boss. It even rewards you for damaging the boss as well, and with its current ff2 nerf, your boost decays very fast.
The faster firing speed @ low health is hardly useful because you're never close enough to utilize it. You hit full boost in 100 damage anyways. The 6 clip is unnecessary and I think it'd be just fine with 4.