In-flight meal service will most likely be nicer on the SEA-SFO route. For example, OAK-SEA and SFO-SEA should both get continental breakfast on an early morning flight, but the snack out of SFO will be nicer, especially since the planes at SFO get catered in the morning, which I don't think is the case at OAK.

OAK is much less delay prone than SFO. It's been almost a daily occurrence between 9 am to 2 pm in recent weeks. However, early morning flights from SFO (9:30 and earlier) do tend to leave on-time. Also, there usually aren't too many delays arriving/departing SFO during the late afternoon/early evening.

Your F ticket does include lounge access, but there is no lounge at OAK. SFO isn't bad, and I haven't encountered any particularly long security lines there.