if you do things on the hob you tend to have to keep an eye on them to make sure they don't burn/dry out etc and there tends to be more stages in the cooking. plus you have to be around to remove from oven
with a slow cooker i sling the ingredients in and stir maybe once or twice if i'm around. not at all if i'm out. ie its much less labour intensive and i can put it on in the morning and so don't have the after work rush of getting food ready. i can prep stuff the night before if i'm busy in the morning (by prep i mean cut up and put into dish).
but you have to cook differently and use very little liquid
They use a lot less gas/elec than if you'd put a casserole in the oven or on top of the hob I think. Have heard they use same amount of power as a lightbulb, but don't know how true that is!
Plus they are very good for cheaper cuts of meat as cooking very slowly makes the meat really tender. I don't use mine all the time, but do find it handy if I haven't got much time later in the day; I do all the prep in the morning, go out for the day, then come home to a lovely dinner! Plus can be good for batch cooking and freezing some if make a big stew etc.
I keep seeing/hearing about slow cookers, but what's all the fuss about? Why are they so great and what's so different about just using a casserole or hob top ceramic, or cooking things slowly in a normal oven? I like meals that use just one pot, but why do I need a whole new appliance when I have a cooker and lots of pots anyway? I work and have kids and I've heard you chop up loads of stuff in the morning and come home in the evening to a perfect meal, which seems convenient - true?? Who can convince me to take up what looks like a good deal on a Russell Hobbs one in Sainsburys? Thanks!