I don't know about Gliere's piano music, but he was practically worshipped as a god by my high school orchestra for penning 'The Red Poppy' and, specifically, the Russian Sailor's Dance from said work, a simplified and transposed version of which we often played as an encore. It's probably his most popular piece, though you wouldn't have a difficult time convincing me there are better Gliere works (I was never very fond of it myself - not enough variation of the theme in the variations, I thought).