Element are more waterproofed, EPS have a water resistant insulating layer added and construction that makes them less likely to let water in.

I have regular Freeriders and EPS. I needed a half size up in EPS (actually ended up full size up but half would have worked).

The pinkbike review is pretty fair.

I got the high-top EPS, very disappointing tbh- it’s warm when it’s dry but it’s barely water resistant, the first splash goes straight through. I reckon they’d be superb in the cold and dry, ie proper snow or high mountains or whatever, but in UK cold and wet I think they’re shit frankly, even caked in waterproofing stuff. I’d rather wear my Freerider Elements and some good waterproof socks in winter.