I think Lonely Planet can describe the Cathedral best:
This gargantuan cathedral was completed in 1997 – just in time to celebrate Moscow’s 850th birthday. It is amazingly opulent, garishly grandiose and truly historic. The cathedral’s sheer size and splendour guarantee its role as a love-it-or-hate-it landmark. Considering Stalin’s plan for this site (a Palace of Soviets topped with a 100m statue of Lenin), Muscovites should at least be grateful they can admire the shiny domes of a church instead of the shiny dome of Ilyich’s head.