One of the big advantages of the Aleph system is the interchangeability of parts. You can swap body tubes, tail caps, heads and light engines around to make whatever light you find most useful at the moment. Since most of these parts are no longer readily available, it would be hard to build your collection now, and the system doesn't make much sense for a newbie to get into. For almost every single Aleph configuration, there is a non-Aleph that gets the job done at least a bit better. The Aleph3 is sort of an exception, it would be hard to beat its throwing ability in a light of similar size.
I love the system myself, but I have 8 light engines of various configurations, 6 different heads, and 8 different tailcaps, along with a number of different battery tubes. It would be hard or expensive for someone to get to that point now.
One other advantage is upgradeability. Its not hard to upgrade the LED when a brighter Luxeon comes along.