Actually, he doesn't consider the day to day life on the ship to bad. After all, as far as he can tell CERTAIN DEATH seems like it was the other option, and here he's got all the other Animorphs plus a non-infested mother with him. It could be much worse, and Marco's aware of that.

...Still, that doesn't mean he's happy with everything. He certainly doesn't trust Stacy. Iniss is still a problem. Plus he doesn't have girls falling over his feet here, which is a major bummer.