What we have that I make almost all of our meals with is my Ninja Cooking System. My daughter gave it to us as a gift, and it is just so versatile that I can make almost anything in it. It has different heat settings, so you can really heat it up to sear the meat for a roast, and then turn the heat down and let it cook, or it also has a timer setting that you can use for when you want to use the Ninja like a crockpot. You first set the heat, and then set the timer for as long as you want the food to cook, up tp about 8 hours, so it can cook overnight if you want to do that. We love to roast a chicken in there, and also use it for a pot of beans, soups like split pea or lentil soup, and any kind of stew. The Ninja also bakes, and you can even make a cake in it; but I have never actually tried doing that yet. One of my favorite things to make is eggplant Parmesan. I do use the frying pan to brown the eggplant slices, then I layer them into the Ninja, add the sauce, spices, and the cheeses (I also add some mozzarella over the top), and let it cook until it is done. Since there is only one non-stick pan, cleanup with the Ninja is easy, too.
Pressure cooker's come with directions and I think it's best to go to it for safe use. Pressure cooker's are good if you know how to use them correctly. I don't use a pressure cooker at all. It's best to check the directions for your particular pressure cooker. If there isn't any directions please go online to check it so you'll have a safe use of your pressure cooker. I don't have a slow cooker either. My Aunt when she was alive like her slow cooker to cook meals for she was a barber and worked all day. She got her pot roast and fixings all ready to plop them into the slow cooker and when she got home her meal would be ready to eat. She said the meat was so tender and she liked her slow cooker. Directions are the best to rely on for slow cookers and especially for pressure cookers.
The electric pressure cookers are safe and easy to use. The stovetop pressure cookers and canners have to be watched but they have pressure relief valves and are safe to use.
I've never used one, but if I do get one, it will be an electric pressure cooker. I've been curious, and wouldn't mind trying one out eventually, but I'll have to price them and see if I can afford it. I do have a crock pot, but it's larger and heavy, so I don't use it that much. I've never cooked tongue, but my favorite tacos are tacos de lengua (tongue tacos), and since a few people have mentioned them here, I looked up a recipe. http://allrecipes.com/recipe/157899/delicious-beef-tongue-tacos/ FYI, I think there are even smart pressure cookers these days, that can be controlled via your smart phone or tablet.