AThese 'element' stacks are built to take advantage of the capabilities of modern browsers, which now includes IE10+. You will find that these look and function great in modern browsers.
Are there some stragglers, sure.
In Opera (currently 12.15): Dynamic can't rotate about y-axis but similar-movement and sides using skew rendering is provided. Perspective renders find with letter text, but numbers appear to create overlap bug.
In IE9: Dynamic & Perspective can't rotate about y-axis but similar-movement using skew rendering is provided and a single moving text face & shadow is rendered. Pop side rendering is not supported, so the single text face & shadow is rendered.
IE7-8: Dynamic will not rotate & renders single text face. Pop side rendering is not supported, so the single text face & shadow is rendered. Perspective text will not rotate, so single text face w/ offset shadow is rendered.
Note: jQuery support will soon be dropped for IE6/7/8 when Stacks switches to jQuery 2.0+, which will affect rendering & animation in those browsers.