Thomas:
For most people, a slow cooker is a godsend -- in theory, you load it in the morning or the night before with things that will be cooking for a loooong time (4-8 hours, although some recipes need 12) and all the flavors will meld into something divine, the meat will be falling off the bones, and you wake up or come home to a perfect meal you did not have to pay any attention to, stir, etc.
And, for many people that is true: I have a friend who makes a "disappearing chicken" for the holidays, and yes, it looks and tastes fabulous and as soon as she declares it done, a line forms and *poof* it's gone, there's no time for seconds or anything. Other friends make pulled pork etc.
I was never that lucky, when I try it, things taste "processed" like canned food and cleanup is annoying.
I should not complain, because usually, I don't have the patience anyway, *and* most things I cook in pressure cookers come out fabulous in less than one hour and folks usually complain about how hard it is to make pressure cooked stuff not taste like canned food, so I suppose we're even.
That all having been said, I'd say try the appliance, worst that happens is it doesn't work so well or you don't like it, then you put it back in the garage or give it to some charity to sell it in their stores.
I have never tried it for say feijoada, but I'm supposing given how everyone says that the best feijoada is made over several hours, it might work pretty well. I would try it, but, gosh, did you know there are at least 3 restaurants around me that make it and we need to help the neighbors with their business, right? ;-)
Have fun!