I have a collection of cast-iron Le Creuset amassed over years of Xmas and birthday gifts, so have never used a slow cooker/crockpot, although I have a couple of busy-working-mother friends who sing their praises.
Braising is probably my favourite method of cooking at long, slow, low temperatures which provides the best results for me. I almost always reduce the temperature called for in the recipe after about 30 minutes to 300 or 275 and I'm in the lid-firmly-on camp. I sometimes add a layer of parchment before adding the lid for a greater seal. It's not meant to be a time-saver for me and I generally put my braise together while also planning/preparing something else for dinner - it's destined for the following day or so, no urgency.
Must be the weather, this is about the 3rd or 4th braising conversation I've had this week.