We were processed reasonably quickly on arrival in Cuba. As in most places, visitors approach immigration officers who are installed in booths behind glass -- interestingly, behind you they have mirrors installed at a 45 degree angle between the ceiling and the wall. I've seen those mirrors at only one other airport in the world; in Moscow.
Bizarrely after immigration, we had to go through metal detectors again -- I'm not sure where they expected us to pick up weapons on the way...
Much like in Egypt, there were taxi drivers soliciting people coming off the plane. I was surprised to find a meter in the cab! In my (limited) experience, they are rare in the 3rd world. And indeed our taxi the next morning didn't have one.
Getting off the plane, one of the first things we both noticed was a characteristic smell. I don't think that's unusual -- it seems to be true of most places. Although in the 3rd world it seems stronger and more characteristic; not entirely unpleasant. On the highway, where the smells lean toward the petrochemical it's harder to tolerate.
Our hotel was not bad for $25/night. The hot water intermittently varied from nonexistent (once) to scorching (once) to simply "not cold" (usual) and one morning I had a large 6-legged friend join me in the shower but at least it was comfortable. Fortunately noise doesn't bother much cause there was a lot of it off the street -- not just traffic, but people and roosters and other cacophonous entities.
By the time I got there, I was fully in the standard paranoid panic mode that characterizes my arrival in an unfamiliar place. I start worrying about crime and harm and running out of money. About getting in contact with people, finding my way around, communicating... I think it's a survival response to just being in an unfamiliar country with unfamiliar people and an unfamiliar system. I went to sleep feeling vulnerable.