So I decided to try it out (helped by the cold weather which meant the gas oven being on at the weekend helped with the background heat) and have had some surprising successful results. I did a Pork Goulash, Chicken in Cider and a Ratatouille with Sausages.
For the Chicken in Cider I added some of my vast store of runner beans from the freezer (defrosted first) and they cooked well without becoming too mushy - which would probably have happened with conventional oven cooking. The vegetables in the Ratatouille were also nicely cooked. The carrots in the Chicken in Cider were initially a little harder, but a quick blast at a higher temperature helped with those.
This is a really useful method to use on Sundays where I've sometimes gone to meeting and been distracted, and have got back late and had to prepare something before eating. With slow cooking I can just prepare it before I leave, and turn the heat up when I come back if not quite ready. Also, by using the full quantities in the recipes, I end up with 2 or 3 servings I can freeze for a quick defrost another time.