My wife was gifted a PC from a friend of ours that cooked Indian food constantly (because, well, she was from India!). It gathered more dust in our cabinet than it cooked food because I do most of the cooking and I was slightly afraid of the thing (due to its age, not due to its purpose).
In a pinch a few months ago I was in a rush to make dried beans and tried it out. I'm not sure I'll ever buy a can of refritos again. You just don't need to plan like you do with stovetop. I made them in less than 2 hours a few nights ago. We have terrifically hard water here in NE and that only makes bean cooking harder / longer. I used to have to do the baking soda trick.. the overnight soak trick.. etc..
What an amazing difference a little pressure makes! Latest method:
Bring to a boil in water (in the pressure cooker with lid off). Turn off the heat and let soak for about an hour. Add chicken stock, salt(yes- I can now add salt BEFORE cooking!), chopped onion, 2 cloves of garlic, some toasted cumin seeds). Then bring back to a boil with lid on and siimmer with that pleasing steam release sound. I swear it was about 45 minutes and I was out of time. Had to serve dinner. I decided if beans weren't done we'd eat them the next day. I took PC off heat. waited a while. then put in a sink and ran a drizzle of water down it and let it collect in the sink around it to cool down the apparatus. Did I mention I was afraid of this monster? A few moments later- the cauldron was opened and wow... already soft! I mashed them with a potato tool and we were having tacos!