Aerobin update: I've now had the 200 litre version for about 2 weeks and very pleased so far. Was easy to put together. The main tip I would would be to ensure the drainage tap is in the 'on' position before you put it together. I would bet that it is otherwise impossible! I've not yet got a drainage pipe and tap for it, but they do sell them.
Started it off with a layer of made compost from the old bin (not essential, the instructions will give you alternatives). I'd been collecting ingredients together and started it off with a mixture of: grass clippings, privet prunings, shredded hedge prunings (hawthorn, blackthorn, firethorn, beech, hazel, rose), kitchen waste (veg peelings, kitchen roll, cooked scraps), chopped comfrey, semi-made compost from the old bin, ripped corrugated cardboard. Like most composting you're looking for a mix of greens and browns. All this was pre-mixed in a tub before adding. We managed to fill it to the top of the aeration device. Watered it with an early morning pee as an activator (thanks OH for that!). Treated myself to a compost thermometer and checked the compost on Wednesday and it had reached 32c already. Levels dropping noticeably.
Filled it all the way to the top on Saturday with another similar mix to before, watered with a little diluted seaweed extract and today it's just under 36c and has dropped again by a couple of inches. I've set up a three tub system by the side of the bin: browns, ie. woody shreddings, scrunched cardboard and paper in the bottom one, and greens, ie. weeds, grass clippings, etc. in the middle one with an empty tub on top. Then whenever we've got a full kitchen caddy, we use the empty tub to mix the ingredients and chuck it in. The instructions do say you can just do layers, but I'm being ultra-cautious!
The next test will be opening and closing the doors, will update on how easy/awkward this is.