I have the Savvy Ultimate Steering.
One of the advantages of aluminum over steel (for me) is that the cosmetics last longer if you live in a rust belt area (which I do). That may or may not be important to everyone. But it's close to the road/snow, and very visible from the front.
It's important to me (because rust is my biggest enemy right now), and I'm fairly certain, apart from accidents, that either option is serious overkill for how I use my Jeep, so their strength difference between the 2 is a moot point for me.
I will say that the steering noticeably feels much tighter and cleaner since I upgraded from the Crown HD steering (XJ), and definitely looks nicer IMO. If I could go back in time, the Currie or Savvy steering would have been one of my 1st upgrades.