It's a matter of taste really. Usually people like to have Trajan Pro (the serif font) in the design, but on the other hand it's everywhere. True, the san-serif fonts can be just as common, but they are standard.
I personally like a bit more how the serif ones turned out. Print-wise, I think a better choice would be the san-serif ones, especially if you want to use the logo in small placeholders or if you want to sew on shirts, for example.
If we're talking about this particular logo, you can certainly use the one you like best, be it the serif one.. and if the need comes, switch to the sans-serif ones if you encounter an issue at any time.
Hope I got the question right. :)