Factory would be better then a manual bleeder if you can afford to get your car tuned.
As it uses feedback from MAP sensor among others to adjust and control boost, eg, closed loop.
Where as MBC does not, just bleeds air from wastegate line,
I used to have an MBC on my car and it was fine, it just needs to be set up correctly.
Like the other guys stated, don't over do it without supporting mods.

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F.B. Racing
01 WRX (STI badged)
2010 XR5 Focus
06 Impreza Hatch 2.0i