FWIW I've had the Aguilar OBP-1 and the Bart NTBT (2-band, not 3).
I found the Aguilar to be pretty transparent. Low boost was massive & tight, high boost was sharp but organic, like glass.
By comparison, the Bartolini seems a little more colored, a little dirtier & cruder but in a good way.
They're both great IMO. I'd use Aguilar if I wanted something clean & dynamic and the Bartolini if I wanted that Bartolini flavor (which seems to complement the Bartolini pickups well for some reason...

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