I’ve got the Ninja dual 9.5litre. When I was thinking about getting one, I read a thread on here similar to yours and the most common thing regret people had was getting one too small. So I got a big double one.
I do not regret it. I’ve only had it a few weeks, but it is really good. As well as being quick and energy efficient I would say it’s also just less bother. If I pan fry sausages I have to keep turning them and get splattered with oil etc. Cooking sausages in there is so easy - just throw them in - they’re really nice and brown in about 12 minutes, and you just pull the drawer out and give it a shake halfway through.
I cooked really nice Cumberland sausage in there in 20 minutes and that would usually take an hour in the normal oven.
Cleaning it is easy (although I am really lazy still!).
It’s good for roast veg. If doing a big roast dinner it’s useful as extra cooking space as well.
You can set it up so the good in both drawers is automatically ready at the same time even if they’re completely different cooking programs.
I think the main thing is that it’s so easy to cook small things with no fuss, eg one child wants a sausage sandwich- just throw in 3 sausages and it’ll be done in not much over 10 minutes with no effort from me!
I hadn’t thought of doing a jacket potato in it, but I’ll give it a go!