Just speculating as to whether the size of links or their formatting (strong, etc.) has a effect on the strength of the "vote"? Links in my sigs, and outgoing between my sites, are done in size 1 usually so they aren't big and annoying.
Some say it does matter, some say it dont. Personally i like to test things out myself when it comes to such things but i have not done so in this case.
I don't think so. It may make it more visible as an ad for humans but even then sometimes it's just annoying.