Saigon is massive and in desperate need of a metro system, or something else to alleviate the traffic. That being said, most things to see are walkable from the main tourist area, and it's quite a spectacle to walk down Bui Vien at night. It's comfortable enough for a night or two, especially as a bookend for a longer trip.
The thing to do is a day trip to the Cu Chi Tunnel complex, about 2-2.5 hours. It's dirt cheap to arrange, but like most tourist destinations in Vietnam, has become super-crowded and like moving through an assembly line. I'd skip it.
My blog serves two purposes: to let friends and family know what I'm up to while on trips abroad, and to give travel advice from the perspective of a fellow traveler, rather than from a guidebook writer.
I'm using a Google Pixel for all the writing and photos, so excuse any errors or blurs.
... full info