One major downside of pressure cooking is that you have to cook every ingredient for exactly the same amount of time. This means that in practice it just isn't possible to cook every element of a meal together, and you have to use separate pots and pans in addition to the pressure cooker.
As much as I love my pressure cooker, I do find it frustrating that I can't just open up the lid and check what's happening with the meal. Cooking is an inexact art form and often the best way to know if the food's ready is to look at it or try a sample. Achieving the correct level of herbs, spices and seasoning is also easier if you can add as you go.
While I wouldn't let it put you off investing in one, the truth is that using a pressure cooker effectively does require some learning. It's a very different process relative to cooking with a regular pot. However, it's not that difficult and most people do pick up the technique quickly.
While they are great for certain sorts of meals, such as stews and soups, they are not suitable for many others, one example being meals that require high-temperature roasting. You can't cook a steak in a pressure cooker.
It's very easy to overcook food, especially when you are learning, as cooking times are so much shorter with pressure cooking. I ate a lot of overcooked food when I first started out, just a couple of minutes too long can make a big difference. You also have to be aware of which ingredients you use, as it's easy for certain foods to be cooked well, while others are overdone. I would recommend using a pressure cooker recipe book for beginners, certainly until you get used to the timings.
