If you are short on time, skip the Orinoco delta and go to Los llanos. You will see everything in Los llanos and catatumbo that you can see in the Orinoco delta and so much more.
We took a private driver from ciudad bolivar to San Jose de Bujas and then a 3 hour boat ride (less time when the duck weed isn't as thick) to the camp we stayed at, boca del Tigre camp in the Orinoco delta, and did not have a great experience. The food was good, but the house across the river from the camp blasted reggaeton and cumbia for much of our two days there, which definitely kills the atmosphere. The camp also had holes in its mosquito nets and mosquitoes are very plentiful. The indigenous people in the area have caught most of the macaws and other animals in the area to sell to the pet trade. There are now so many people living in the area that the heavy boat traffic scares away most of the animals from the river, making it hard to spot them in the jungle.
That said, it is cool to be in the middle of such a massive delta. The water is warm so you can swim in the river and the guides added a morning bird watch and afternoon bat viewing after we asked. The guides pointed out some toucans, we saw one group of howler monkeys, and there was a really cool island that had thousands of parrots roosting on it. The guide also took us through the jungle to show us various medicinal plants and different things you can eat, like heart of Palm, and a grub that is an aphrodisiac--this is something you won't get in Los llanos or catatumbo. But much of our time was spent visiting an indigenous village and the guides family's home, where, instead of learning something about the village or the people, you just get pressured into buying tons of trinkets. On the plus side, the items are handmade and much cheaper than the same trinkets you find in gift shops around the country (less than half the price in general). The hammocks in particular are amazing and not made out of synthetic fiber.
The guides pointed out a decent number of animals, but they usually didn't know the names of the animals in Spanish or English. The guides were also late almost every day. On our last day, the guides told us to be ready to leave at 5am sharp to catch our boat so we could catch our flight. They showed up 45 minutes late and then shuttled back and forth between their houses, making us arrive for our flight after it was supposed to leave. Thankfully our flight was also delayed. The guide and the cook also forgot every single meal that we were vegetarian and put meat in everything even on the last day after multiple reminders (we were the only people in the camp which made it even more shocking that they couldn't remember we were vegetarian).