Will there be a decent amount of customization available?
Ships alone have modular pieces that make up the whole of the ship. So a tier 1 Sentinel could have 4 different wings, 8 different bodies, and 8 different engines just for the WAY IT LOOKS. And this is just ONE SUBCLASS. There are three classes, and three subclasses of each.
There will be further customization for the cockpit, and additional details on the exterior of the ship, too. Also, there will be primary, secondary, and tertiary colors to customize, and the insignia as well. But I may have said too much; there will be more regarding this in a future dev update.
But all that was just the way your ship looks. I didn't even crack open the various Specials and Passives each subclass could have, nor the differences of equipment slots. And we didn't talk about the depth of the itemization, either; each piece of equipment can literally change the way you play. But we also didn't talk about Devices, and the unique modes you can unlock on them. And we didn't talk about the Perks.
To summarize: yes, decent amount.