Delete Google account or factory reset?

[comandoed]

I have Verizon XT912 flashed to Cricket.
Recently I cancelled my Cricket account and got a new phone with Metropcs.
I would like to sell the XT912 on Craigslist or to a friend.

Should I do a factory reset or just Remove my Google account before I sell it?

I believe it has a blank microSim that was used just to get the flash to work.

 

[Einsteindks]

Factory reset, wiping phone storage as well.