By the way, my 3.5l slow cooker is large enough for a family of 4 - a 6.5l one is going to be huge sothink about where you're going to store it. I've also read that they need to be filled about two thirds in order to work best.
I cook whole chickens in mine too ~ I stuff it with a lemon, sprinkle it with black pepper and put in on some scrunched up foil balls in the bottom . . . it comes out perfect!! You dont need any extra water as the steam from the cooker will be enough . . hmmm me thinks it will be on my 'menu' this week!
Yes but the cost of running your oven for 6-7 hours will be a lot higher than the cost of running the slow cooker. The further down the cooker you go the more energy it takes to run in so the oven is the highest energy burning source.