stereo amp vs monoblocks, any advantages?

Good question.

I'm stretching here a bit , but the main advantage I can see for monoblocks versus say a dual-mono single box design is that you get a dedicated power cord to each side. That would be beneficial I think if the amp draws a lot of current andassuming your power circuits are capable of delivering more current to each this way than otherwise.

There may be some advantages in exposing line level circuitry in the amp to lesser EM fields produced by a single power transformer nearby rather than two as well.

That's all I can think of.

You gain absolute separation between the channels of the amp and much greater flexibility in amp placement. You don't have to worry about such things as weather to biamp horizontally or vertically. You don't necessarily gain extra power, theoretically you can make a stereo amp of any size, but two monos are easier to manage than a stereo one, and , as previously mentioned, what is going on on one channel never affects the other. Monos take more room, 2 power cords and are inevitably more expensive, otherwise they will always be better assuming same quality otherwise.

When you are buying a "Dual Mono" amp on a single chassis check on what they mean, the term is used very loosely, not consistent even with the same company. Some of the Musical Fidelity amps , for example, have two separate transformers, one for each channel, and others have one large for both. Both are called 'Dual Mono". The more parts of the amp that are shared between the channels the more they will interact with each other.

My Stereo IcePower amp has separate compartments for each channel. Each module has own regulated supply. Monoblocks still would be better because they shorten speaker cable.