Well there are three skins downloaded by default I believe and 'newer and better skins' is plural and doesn't sound like replace the default skin to me.
Define professional, have you tried the no skin option ?
I understand that the poll option was plural, but I am personally only referring to the default skin, so just one skin.
I have tried the no skin option and I do prefer it to the media player look of the default skin. By professional I mean clear, clean, crisp. I just don't think the look of a media player suits and anti-virus program, but that is, of course, just my opinion. Examples of some of the extra skins that I do like are: Corporate, Lite-On, RejZor-Sharp, and possibly aVist.
However, I would always prefer to use the skin created by the company which created the program.