Vantaggi
Amdocs has a strangle-hold on many of their clients. Once they are embedded, it is very difficult to remove them. This creates a relatively stable revenue stream, which avoids many of the ups and downs that hit similar sized companies.
Svantaggi
Company culture is over-rotated on "anything the customer asks for". I've seen managers promise availability of staff over weekends and holidays without a second thought. Product "roadmap" is minimal compared to competitors. Amdocs product evolution is largely driven by funded development from customers- not an internal vision. Company culture is 100% Israeli. US-based management is often over-ruled by Israel, even when it violates state or local laws in the USA. As an example, they require US employees to sign non-compete clauses, even in states where this is explicitly forbidden.