Intro: I never like articles with a title ending in a question mark. You know what you're going to get: no answer to the question. Therefore, they are typically filler. Yawn on that. So here is my question and answer title. Let's get to the point right off the bat: Adobe Reader is a security risk.
OK, it's not like anyone's Mac got pwned by using Adobe Reader. There is no malware targeting Macs that I know of that weasels its way in via holes in Adobe Reader. So really there is no major alarm going off telling us to kick Adobe Reader off the bus for having cooties. But considering that Mac OS X is the safest professional operating system on the planet (not that I'm dissing Linux mind you), avoiding Adobe Reader at this time is a very good idea.
Me, I'll still continue to use Acrobat. I'll still keep Reader around for when I absolutely need it. And there are indeed times when I require Reader. But I'm also going to keep an eye on the latest Reader problems and continue to update it (manually!) when updates are offered.