Mission Bay, however, being shiny and new is probably the most promising over the next 5-7 years since all that is now new, and therefore, probably at their lowest value now. I've included a link to schematic of what's going on in MIssion Bay for you to check out.
Mission Bay has a ways to go ... they still need to finish building all the buildings! Just a few thoughts to consider. I'd also recommend walking around at different times of day and in the evening (although not on the block that OJ grew up on!).
Potrero has good access to 280 -- Mission Dolores is not far, and is a straight shot to the 280 entrance. There is a Whole Foods now on Potrero (bigger than the wonderful BiRite) and many more newly finished condos near the gift center so there should be lots of changes; and the new Mission Bay area will be transformed in the next few years, being right next to Potrero Hill that will have an impact on the area.
So I think it depends on how long you are thinking of keeping a property. Feel free to email me with any questions. Happy hunting! I love these two communities as well.