If I were to tell you that prices generally go over asking in Potrero, but you had your sites set on a condo that is overpriced, I wouldn't want you to blindly overbid because that is the neighborhood trend. Instead you need to look at the comparables, determine the value for yourself, and offer accordingly. You can also get a sense from the listing agent about the activity and interest. That will let you know if there will be any competition.
Alas, if it is numbers you are looking for, in the last six months there were 33 condos that sold in Potrero Hill. Only six of those sold under the asking price, and five of those were at the low end of the price spectrum. Four properties sold at asking, and the remaining 23 condos sold over asking. I hope that helps.