I haven't been to many weddings, but the one that I did go to that also had a seating chart was really thoughtfully done -- I knew the bride, vaguely the groom, and one of the bride's guests as well as my internet-brothers who I went with. The bros and I were at the Internet People table with the one person we did know, her husband, and another couple. We got along excellently, to the point that one of the other couple wound up recruiting me for a work thing; I stayed there four years, we're Dreamwidth friends, and we'd work together again.

So it can go really well! I was surprised by how well it went.

We were last-minute substitutions. It was a destination wedding, three of the family guests got sick, and my bros and I were in San Francisco within driving distance.