I have owned both of these, sold the CAE to get my last Ecstasy. The Ecstasy wins for me, hands down. The OD 100se is definitely more "metal". Not as sweet or spongy as the Ecstasy, more mordern. A bit more articulate, but definitely too hi-fi for me. Better cleans on the OD 100, but you can dial in great cleans on the Ecstasy if you spend some time with it. I haven't sampled the other CAE OD 100's and I hear the Pete Thorn version is killer (I would actually like to check it out someday).
Really, it comes down to what you want to play. Hard rock, etc, the Ecstasy gets it. Metal (particularly if you are going for a Metallica vibe), the OD100SE would be a better bet.
BTW, if you're looking for a good amp for rock/hard rock and can't afford the Ecstasy, check out the Zinky Velvet 50w head; those are killer and for me the closest runner-up to the Ecstasy that I have found. 6L6 tubes, but when you get playing, you hardly would notice the difference between them and EL34's. Having said that, I am getting another Ecstasy, ASAP.