I had the same reservation. Actually I still have it to some extent. The Amel system is good but it is very much dependent on proper maintenance and the condition of your (main)sail.
The Mizzen is hardly ever a problem but I’m not big on the way the mainsail works as you have hardly an idea how much force you are putting on the system. The only thing you have is your eyes, your ears and two switches. I think I would prefer the outhaul working unidirectional with a slipping line when furling in the main.
That said, with proper care and careful operation the system will be quite reliable. There are some current limiters in the system to prevent you from really messing up the system. So the motors will halt when too much force is put on the system. On the A54 Amel introduced short battens in the sail that do add some complexity but also enable an increase of the surface area of the main sail.
I have had some minor issues with the main but most of them were related to a old mainsail with a very floppy leach. My new mainsail rolls in much nicer.
This is my first in-mast furling system so I have little to compare but I do think that slab reefing on a sail this size is a challenge as well when shorthanded. I guess it is a trade-off.
The good thing is that the system is fairly simple compared to some other systems in the market so there is not too much that can go wrong. I think the most problematic are the 90-degree gearboxes on the outhaul and the main spindle for the older Amels.
Hope that helps,