I agree with OP about that specific attack. Even as a SMN main it's hard for me to avoid them and I have pretty much no restrictions on my movement. The hitboxes are just a little bit too big, I think adjusting them to about 85% of what they currently are would be ideal. Other than that, I haven't felt any problem with the difficulty. If anything, bosses should have their health buffed, they all seem to die too fast.