Class A amps or Class D?? – which sounds better??

Amplifier performance and synergy depends on the other components, and cables in a system. I have read alot about the advantages of Class A.amps Though an older amp design, do class A amps necessarily sound better than Class D digital amps like Nu-Force, Bel Canto, and Wyred4Sound?? These class D amps supposedly run more efficiently, with less heat and noise and are smaller in size.

I have a friend who has a Musical Fidelity A3CR power amp and a Bel canto pre-amp, and a pair of Spendor floorstanders. The MF amp is at least 10 years old, and no longer made. I have listened to the amp in his system, and it does sound very good. Most noteably is its across the board smoothness. However, I think its performance is system dependent, and might be a liability in other systems. Would like to hear comments and opinions about these two amp "designs", and if one sounds better than the other, OR JUST DIFFERENT.

BTW, I am not sure that owning a 10 year old amp like the MF A3CR is a good idea, despite its class A rating, and a few positive consumer reviews I have seen. Thank you