Zihautenejo is a beautiful small city with a moderate sized bay. Comfortable anchorage can be taken in the bay despite the swell because the swell period is so long that it is hardly noticable. We anchored in 20', sand, just outside of the fleet of local powerboats. A marina also exists at nearby Ixtapa, but we heard that the marina charges fees as if it were much nicer than it is.
Town is quite pleasant. Downtown is along the harbour and almost anything can be purchased within walking distance.
Zihuatenejo is almost 200 nautical miles east of Manzanillo. Given this distance, I wouldn't recommend a stop for anyone planning to turn around. Don't get me wrong, Zihuatenejo is a wonderful town. But you're considering putting close to 100 hours on your engine for the round trip from Manazanillo, and I don't think it is worth the time and effort.