I believe either topology can be as good as the other, it's just down to the price you want to pay for the functionality you need... personally I prefer separates. My preamp has inputs for MC (transformer) and MM cartridges, four other analogue inputs, a 64dB attenuator with 128 steps and four individually powered stereo pair outputs. That gives me the functionality I want with little compromise to quality. Actually, I think the volume control is a weak point in many amplifiers and a well implemented stepped attenuator can make a real difference on its own.
Are integrated amps technically better than separates?
I'm assuming we are talking same class of amplifier and the integrated has the features you want. I'm thinking the integrated could actually be an improvement over separates due to being a more "direct" connection. Taking away the flexibility factor of separates, is my line of thinking correct?