It's more about usable surface and standing area

Our kitchen island tends to be the center of social functions, especially New Year's Eve. Since we are in California, things aren't as spread out as I would like. We have a decent size island (about 42" x 72") but I would not want it disrupted by a prep sink.

Unfortunately, I don't really have another place I could put one. not sure I would want one if I could. The non-island option seems reasonable if it could be co-located with the main sink, but I really like an island that is not used as a cook station, be it prep or cooktop. I like being able to congregate on all sides.