Are Monoblocks better than Multi-channeled amps??

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.