The 7:10 AM ferry is operated by Blue Star Ferries, specifically the Blue Star Chios, which is a traditional ferry (Hellenic Seaways and Blue Star belong to the same group, "Attica").
The other, faster ferries are Seajets catamarans, which are completely different in terms of comfort and style.
Seajets (fast but expensive) are configured like large movie theaters with multiple seating areas and assigned airline-style seats. There is no real outdoor deck, except sometime a large terrace at the stern of the vessel with virtually no seating.
Conventional Blue Star Ferries are similar to small cruise ships when it comes to facilities, decks, and amenities. Much more pleasant.
The 7:10 AM Blue Star Chios: https://youtu.be/PmYyZTUQZZY
A Seajets Ferry: https://youtu.be/I8TzBaiRWfA
You already have much of the following information in another discussion thread (seeking advice on first trip to Greece in late August 10 days).
So, at the risk of being repetitive:
In Santorini ferries depart from Athinios Port located south of Fira (the "Port of Thira" generally refers to the old cruise ship port). There is no direct bus from Oia to the ferry port. You must first take a bus to the main hub in Fira, the capital. Buses from Fira to the port depart between 60 and 90 minutes before each ferry departure.
My choice would be easy: I’d take a taxi from Oia to catch the 7:10 AM Blue Star.
Give yourself plenty of extra time for the taxi ride. The road leading to the port is a steep switchback/hairpin-turn dead-end that gets extremely congested with all the buses, trucks, cars, and vehicles arriving and leaving, not to mention the absolute chaos caused by thousands of passengers at the port itself.
Here is a video showing the road, though in the opposite direction (heading up from the port toward Fira):
https://youtu.be/nwp4-rc0ygk