We purchased the litter robot about 5 months ago and i cant recommend it enough.
We have three big cats, a fat Russian Blue and two Maine Coons ( 7-10kgs).
They took to the bot almost immediately, and after a week of leaving the old tray to fill up with the fresh robot next to it, they all transitioned over without an issue.
This thing is a godsend. With all three cats using it, we empty the tray every 2nd day or so, and it is so easy. No more scooping, no more breathing in litter dust, just open the tray and replace the bag. We do sometimes have to open the tray and shake it so the clumped litter is evenly distributed across the tray - it tends to deposit in one spot and it will flash "full" when it isn't completely. This takes about 5 seconds.
One of our cats likes to stand when he urinates and the urine would spray up the wall of the old tray ( a big plastic tub) and often our wall as well. With this, it is completely contained, and when the globe cycles it clumps the urine and we don't have an issue - at worst we wipe down inside with a wet wipe, considerably easier than cleaning the whole wall.
The smell from the litter is almost completely gone now, and if you set it to cycle faster after a use it is practically odourless.
The only problem we have had is stopping the Maine Coons from trying to play with the clumped litter as it cycles - they think it is a great game and come running when they hear the machine start to spin. The noise is much quieter than expected and eventually becomes background noise you don't notice anymore - like a passing car or cows in the back paddock.
The only suggestion we have is to pay for the liner bags from Cat evolution - we tried using coles and woolies ones but couldn't ever find anything that fit as well, and they were never biodegradable either.
Its a big investment, but 100% get this robot - its the best cat "thing" we have bought.
I had my globe for 3 years now and absoutely love it. Our removalist broke it on our move and it was a long 3 weeks to be reimbursed and have a new one sent to us! Having to scoop a litter tray reminded me why i bought the globe in the first place! Theres less mess with the globe, my hands dont have to touch the litter scoop and the laundry doesnt smell as its all contained in the base with a charcoal filter to eliminate odours! 100% recommend spending the cash you will thank Mary later xx