Altea Fly, as it was officially known at one time, is a very comprehensive and sophisticated system, along with its counterparts, the hosting system (Altea Plan), and the distribution system (Altea Sell). They might well be the best there is out there.
As they were designed for a global market, rather than specific airline customers (although the launch customers were, I think, QF, BA, AY, and SA) they had to take into account a multitude of needs and this led to over complexity.
Amadeus is fundamentally a French company, whatever they may try to tell you differently, and although the French do some things very well (selling themselves and ther products above all), they are spectacularly bad at web design, and these are web based products, as they try to add too many bells and whistles, at the expense of the basics, as they love to show how 'clever' they are.
In my view, this is what all the Amadeus product range suffers from. Despite that, I repeat, they are probably the best there is.