Here's what I've personally seen.
At the squadron level, the culture is almost identical between the two services. You have the different types, fighter guys are different than helo guys, etc, but at the end of the day I've seen pilots from both the Navy and Air Force bitch about mostly the same sorts of things.
The biggest cultural difference is the willingness to make a decision without asking the boss, which stems from the way the services write their instructions and give permissions. In the Navy, if the instruction doesn't say you can't do it, then it's on the aircraft commander to decide if what they are doing is ok. In the Air Force, if the instruction doesn't say you can do it, then it's not allowed. This isn't just an aircraft thing, I see it in ground duties as well. It can be hair-pulling frustrating trying to get AF non-flying types to do something without them being directly told to do it.
I felt like I had a ton more autonomy and freedom to do whatever I wanted (within the rules) in the Navy than I have in the Air Force.
Additionally, interaction with higher levels of command is more evident in the Air Force. There's a definitive line that exists between the squadron and wing in the Navy that doesn't exist in the Air Force. Maybe I've been unlucky but everywhere I've been the group and wing is more active at the squadron level than I ever experienced in the Navy. That can be good and bad, but in my opinion it's bad.
That said, the flying, as a junior guy, is fairly similar. You'll get qualified, you'll deploy. As you gain experience and PCS, in the Navy the trend is that you are either on flying orders or on not, and that happens in the Air Force as well. However, in the Air Force there are a lot of jobs that would be non-flying in the Navy that still lets the AF pilot fly. I'd also argue that the AF gives senior (O-5/6) guys more opportunity to fly than the Navy does.
Collateral duties (Navy) or queep (AF) is just all the extra crap that aircrew are expected to do. It's the same really regardless of which branch you are in.
Deployments in the Navy are mostly what you'd expect, 6-9 months on a boat. AF deployments are changing compared to the days of Iraq/Afghanistan, but they still exist. Regardless of where you go, you will be on the road either TAD/TDY or deployed.
If you are dead set on flying fixed wing and nothing else, go Air Force. While the specific platform is impossible to predict, you have a lot better odds at getting a fixed wing platform.
If that's not a big deal to you and you'll be happy flying whatever, I'd recommend the Navy.
