Are Monoblocks better than Multi-channeled amps??

Typically, when a manufacture produces mono blocks they will use higher level components and beefier power supplies etc. Everything is built to a price point, and mono blocks are generally the manufactures statement product.

Yes, BUT: That does not mean cheap mono blocks from company A are better than a we11 designed multi-channel amp from company B.

Or that dual monos in a single case aren't just as good as separate monos. Dual power supplies are a step up but still don't beat monos for channel separation or crosstalk which really is the point imo.

Good thing I used words like "typically" and "generally".

Also dual monos on a single chassis tend to get very heavy and large.

In general, monoblocks are better than multi-channel amps, mainly for 2 reasons:

1) Separate power supplies provide more instantaneous current to the output stage.

2) Because the L/R circuitry is housed in separate chassis, there is no interaction between the two (better separation and soundstaging)

Whether the added cost is worth it depends on your priorities, wallet and space.