Personally I avoid separates when possible, even if they cost the same, because the multiple power cords, and even worse sometimes the need for multiple room AC branches from different circuit breakers, escalates the possibility of ground loops. Ground loops can initially confound even some
well-known EEs in their Reference rooms! Also the improvement (generally) of lower noise floors per device, at least in theory, often gets thrown out the window if every device in the chain doesn't have a variable input sensitivity and output level controls so one can optimize the overall system's gain structure from device to device.
A common similar problem is people who buy outboard DACs—because they're in vogue these days—and then muck up the performance of their existing AVR or prepro because they suddenly have to engage its mediocre
ADC to re-digitize the incoming analog signal from the new DAC (say because they rely on room correction and bass management, which nearly always needs to be done in the digital domain) whereas when they previously used their device
connected digitally that noisy extra step was bypassed.
