I'm still shocked that you ever played Civ 4. Securom is much more intrusive/invasive. It installs high-level drivers, monitors other programs, and will refuse to run if it even detects some programs. Steam is much better.
Also, I think Stardock have lost any credibility they had. Between delivering a terribly broken game (despite knowing about its problems) that continues to be unfinished, and having a terrible refund policy (if you preordered more than 3 months before release, you can only get store credit. And only 75% credit unless you agree to spend time working with tech support). Oh, and putting DRM into impulse that makes Elemental refuse to run if it detects a modded EXE (Such as the large-address fix that stops crashes on larger maps).