I've been enjoying my CODE1 with brass spikes and my Dietz with Code 1 Side effects lately.

I would have to agree with Alex regarding the "one ring to rule them all" statement for the Ultra Lights. I Love them now that they come in colors. I run UL's on all my SE equipt yoyos EXEPT the Dietz I feel the Dietz plays best with the Dietz SE's but for the 54, CODE1(no longer have one) DANG, CODE2 and new Proto which I played for a bit they all have AL ULs and I love them like that!!!

Al ultralights for my 54, AL legos for my CODE1 (closest thing to ultralights).

Brass spikes for the Dri-YWET. It's so heavy and fun to play.

Sounds fun, haha.

My current setups:
54 (nickel) w/ brass Lego
CODE1 w/ aluminum ultra lights
Dietz (nickel) w/ aluminum spikes
CODE2 w/ aluminum Dietz

I have brass domes in my 54
and in my nickel dietz I have dietz SE but blue! what a lovely combination

Some side effect notes after experimenting with some setups today...

Stargazer v1 retrofitted with a Ni Dietz hub.
SE: brass spikes
This combo is pretty great due to the extreme rim-weighting of this yoyo being able to handle heavy center weight and remain very stable. The result is tons of momentum that really powers this yoyo through combos. Fast and heavy.

Dietz
SE: aluminum spikes
I easily prefer full size over undersized yoyos therefore I haven't figured out what I like on the Dietz. So far I don't like how a string-centering bearing or too light or too heavy SEs feel on it. For now, the combo of flat bearing and medium weight SE feels pretty good and a decent compromise between speed and stability for this yoyo.

CODE 1
SE: aluminum ultralight
Also, string-centering bearing. This combo feels really really great on this yoyo. The result is lots of speed and maneuverability with stability. Very fast, light, and great for small moves (think Dang-style chopsticks). Love it.

54
SE: brass ultralight
For this throw too light yields not enough momentum and too heavy just increases the proportion of center to rim weight to an uncomfortable degree for a high-walled yoyo. I keep coming back to the brass ultralights on the 54 and they always feel just right.