Crossovers: HU vs amp

[Crossovers: HU vs amp]

Would like to know what you guys prefer and why.  The HU seems to have more precise control and you can change the slope as well.  If using the HU crossovers, should the amp be set to full?

[Need advice for amp power to sub]

Thanks for your replies....

in regards to gain setting, my HU is 6v so the gain is already set low , maybe 1/4 full or less (used DMM to set)

 

i just had to ask this question because most articles recommend to match amp power with rms rating of sub(or close to it). So I was never sure if I was hearing close to the full potential of this sub.  It only really comes alive when close to full volume, but I assume this is normal, at least with sealed boxes.

[Need advice for amp power to sub]

I have a Boston acoustics pro 12.5 sub(4 ohms) in custom box at Boston specs (sealed 1” mdf).  It is rated at 1200w rms and iam now using a 600w rms(Hertz class D).  Although it sounds pretty good, cant help wondering how much difference a 1000-1200w amp would sound compared to the 600w amp.  Need advice from people with experience trying different amps with the same sub.