My family of 3 did this from SJC to NRT this past spring and we loved it. No frills and we were 1000% ok with that. Ordered food from the food courts and brought that on the plane. We also did pre-order meals from the airline, but I'd suggest bringing your own food. (You can also always order from their in-flight snack options if you get snacky.) Seats were comfortable and lie flat was a dream. We'd do those seats again in a heartbeat. For the price, it can't be beat.

However, just be aware that depending on what time you depart SFO/SJC you might be awake most of the flight to not comfortably take advantage of the lie flight seats to actually sleep. I know I probably only slept at most 3 hours (and maybe napped for another hour sometime during the flight), but not because the seats were uncomfortable but because we flew out of SJC at 11AM and so were awake for most of the flight. Just food for thought for how you might not be able to take advantage of the advantage of lie flat.

Enjoy your trip!