Both trailers are alike in the sense that they are both somewhat underwhelming. They're not terrible but they're just kind of, well, at best...competent.
Obviously Discovery has higher production values, but that in and of itself doesn't compell me to watch. FX these days are sort of taken for granted. The constant gee whiz in Guardians of the Galaxy 2, for instance, or Doctor Strange before it. We've reached a point where I've largely lost the ability to be awed by spectacle alone.
The lack of a real "hook" in Discovery is something everybody seems to be saying, and with The Orville, the tone seems to be sort of half-way between serious and parody to the point where it comes across as Galaxy Quest with fewer/weaker jokes. Also, I just don't find Seth a very compelling screen presence as an actor. He just appears constantly smug and self-aware, like he's always breaking the 4th wall even when he's not. I think Tim Allen was perfect for that kind of role.
Million ways to die in the west was a bomb. So I don't think Seth has really proven himself as a live-action actor. His dialogue works best coming out of other actors' mouths (like Mark Wahlberg) or through a cartoon character that can project more interesting body language. I think Seth in live-action is best as a "personality" like Oscars host.
I'm kind of rooting more for The Orville because it has a lot of potential if they can just get the tone right.