Big caps v Little caps

What do you consider small vs. large capacitors in mili-farads?

I wasn't aware that brands had to be 'unusual' or 'old' to use only one large-value filter cap per channel in the power supply. Amps I've owned from Classe, Conrad-Johnson, and VTL have done just that. Some even sound(ed) good. The McCormack DNA series, which I just bought one of, takes the 'modern' approach, hence its Distributed Node Amplifier moniker (the smaller caps are 'distributed' near their respective output devices, not clustered near the power transformer). I've wondered though, with this topology, do the power MOSFETS wind up foregoing any potential source impedance benefits arising from filter capacitor paralleling? Or is the power supply actually conventional and the 'distribution' just cosmetic?

Another reason is that the large can type caps are connected to by wires but the multiple small cans are pcb mounted which would add parts cost but lower assembly cost and lower inductance.

First of all, the high-voltage filter capacitors have a certain size and in most cases even a low-capacitance/high voltage filter caps are quite large. It will probably require much larger space to mount 10 100uf/300V caps than to mount 2 x 500uf/300V + the price of first ones is technically much higher than in second case.
Higher collector voltage for SS or higher plate B+ voltage for tube amps dictates higher capacitance for filtering larger pulses and certainly higher energy storage to supply the output stage during peaks.

IME it depends, EG.

if we are retrofitting a clasic tube amp, we may have to go for only as many good filter caps in the original spot,s unless there is a lot of room elsewhere, but wa can often raise the value uf wise while staying near the original dimensions, if the rectifier/s are up to it, (rectifier tubes generally aren't), and if we have a choke, or can fit one in.

you CAN get most of the ESR benefits of paralleling up small caps, with some modern large electros at least, AND their is always bypassing.

All the filter caps in my 2 modded baby Leak St20's, are bypassed with ladders of MF polyprop and polystyrene caps.

Tim B