I'm on the return flight from my Cuba trip. I was able to shoot every day, mostly with the Mamiya, and some with my Nikon. I also broke out the iPhone and my Nikon d800, but I won't say any more about those tools.
Here are a couple of observations for US travelers:
1. Nobody really cares or digs into why you are going. Just choose the "People to People exchange" option. After all, you'll be communicating with and photographing people. On the way out you just check a box. On the way back the US Customs guy said "Why did you go? People to People?" I just said yes and he waved me through.
2. The Cuban customs and security folks *will* X-ray your film. They refuse to hand inspect, no matter how I pleaded. I cringed as I watched my Delta 3200 and to-be-pushed Tri-X go through their machine, once on the way in, once on the way back out. At least it was the "film safe" x-ray machine. Hopefully it will survive unscathed. I'll know soon after a darkroom session.
On photographing people: Some of them are sensitive to being photographed. If they point their index finger up and wiggle it, that means "please don't take my photo". Seems worth respecting. I only violated it once, but I was releasing the shutter as the young daughter of an elderly woman in a doorway started to wiggle her finger. Too late to stop. I won't print or post that image. The gesture can be subtle, so look for it.
Learn a little Spanish. It goes a long way. Many Cubans speak some English, so getting around really isn't hard even if you don't have a translator with you, especially in Havana.
Walking the streets of Havana felt safe at all hours. Be careful of pickpockets in crowded places.
Here's some advice for those who are into cigars:
Don't buy from touts who approach you on the street. You won't get good quality. Or, perhaps I should say you'll get what you (over) pay for.
High quality Cuban cigars are readily available from the factory and better cigar stores. Prices are less than overseas, but don't expect them to be really cheap. If you travel out of Havana into the countryside, visit an independent tobacco grower. They get to keep 10% of their tobacco for private sale. You can buy wonderful organic cigars, from tobacco cured and rolled by the grower, with no preservatives. The farmers cure the tobacco typically with a spray of rum and perhaps sugar, vanilla or honey (each has his own recipe). They eventually roll them, and sell bundles of them wrapped in palm leaves. Beautiful, highly photogenic, and if you like cigars, a very fine smoke. They make great gifts and are cheap for the quality.
If you know a local, you can get the cigars local Cubans smoke. These are sold in packages of 20 for *one peso*! I tried one. They are not fine cigars, a little bit harsh, still a good smoke compared to average US cigars, but it's how the local cubans manage to enjoy cigars every day (they smoke a lot of cigars there.) It is quite likely this is the sort of cigar you'll get if approached by someone on the street. They'll probably be packaged into an "authentic" cuban cigar box. Be careful.