Sidenote: do you consider irregardless a word?
Regardless is much more clear to me. I have to stumble over "irregardless" because the grammar police lights sound German in my ears. I usually know what it means, but it's been drilled into me that it's incorrect, so...no, I don't. But I'm not a ninny about it. It's a sign to me that someone doesn't take language as seriously as I do, but that can be okay in the grand scheme of things. And if you find that using it suits you, then so be it. But that brings up another issue about whether you're speaking for yourself or speaking to communicate.
Long answer short? No, I don't consider it a word. But descriptive grammarians have a way of winning in the end over prescriptive grammarians, so you know...
It's kind of like "couth" wasn't acceptable for so long. You know what the person is saying, but that doesn't make it as easy as just using a better adjective.