If it's just that you have to authenticate every 15 days, I don't really think it's that big of a deal. Let's be honest here, if you're a PC Gamer, you have internet sometimes. It might not be a strong connection, but I can't imagine that there are many people who game on a PC and NEVER have the computer hooked-up to a line. Even if you game on a laptop that you like to keep portable; you put it online from time-to-time. Especially if the authentication is automatic; unless you go for more than 2 weeks without putting your computer online, then you probably never even have to think about it.
Mind you, I base this on what I've read in this topic, feel free to give me specifics if my chain of logic isn't accounting something.
Edit: Mind that I'm generally against DRM, but if it's on the sidelines so that I can ignore it and doesn't otherwise hinder me, then I'm willing to give a little slack on the issue.