I had the Imperial last year (and the Ion this year). I'm not a Burton fan, but they're just that comfy and solid, albeit somewhat pricey. Haven't had a chance to try Celsius boots yet, so I can't really comment other than regurgitating what I've read, which is that they're great too.
16 NS West . 15 NS Snowtrooper BIA . 13 Salomon Pow Snake
15 Now Drive . 14 Burton Genesis
14 Flow Hylite