We did the bus trip to Barra several years ago. It was a nice scenic trip maybe 10+ hours on the winding coastal highway. Spend a few extra pesos for a daytime premier class bus with seats much like airline first class. Get seats on the port side so you can “sea” the coast.

We got the impression on our Mexican bus trips that most of the riders were "regulars", who were not at all interested in the scenery. Every passenger who wasn't clearly a tourist had the curtains closed the whole time, making the interior of the bus as dark and as cold as a cave. (They turn the A/C up to MAX: wear a sweater). Opening the curtains to see the scenery flooded the bus with brilliant Mexican sunshine - and woke-up half the passengers.

Where is the Gold Star bus station in Zihua?
Further north is White star the same company or completely different?

So, day time up the coast sounds good to me.
Not so worried about shaving time off the trip as long as it gets there the same day.

Estrella de Oro and Estrella Blanca are separate buslines. Estrella de Oro is always in a separate terminal from the rest of the bus stations (except in Mexico City, if I recall correctly), but usually within easy walking distance, sometimes right next door to each other. Estrella de Oro doesn't operate where you're going so not a problem outside of Guerrero.

Getting to Zihuatanejo-Ixtapa - Bus Stations & Buslines

So, day time up the coast sounds good to me.
Not so worried about shaving time off the trip as long as it gets there the same day.

We have taken many bus trips all over this country, on all classes of buses.

Whenever the option for a First Class (or higher) is available, that's the way to go. If you are going on a scenic route and have a choice, go during the day. It is quite beautiful going north up the coast from here, we recommend the bus, during the day, the highest class you can get. You will have a great ride.

Like stated above, go to the bus station, read the boards. Questions? Do your best and smile, you'll get the information you need. Be Brave!!

Excellent reply!

I would add to also be FLEXIBLE. You can often shave trip time by changing buslines, though sometimes that means going to a different bus station or awaiting a bus on the side of the road (only Estrella de Oro has a separate station from the rest of the buslines here in Guerrero, I'm unaware of other buslines that do this anywhere else).

Whenever the option for a First Class (or higher) is available, that's the way to go. If you are going on a scenic route and have a choice, go during the day. It is quite beautiful going north up the coast from here, we recommend the bus, during the day, the highest class you can get. You will have a great ride.

Like stated above, go to the bus station, read the boards. Questions? Do your best and smile, you'll get the information you need. Be Brave!!

Just make sure to buy the Mexican auto insurance if you decide to rent a car.