I know its been battered around before but I'm about to buy new screws so thought I'd ask if anyone has fallen on or tested those fancy light aluminum Petzyl ice screws.
They seem perfect to me except I haven't found if they are as strong as the steel ones. TC

I doubt they are strong as steel screws, but screws rarely fail due to material failure, they fail because of poor ice or are poorly placed. My concern would be for their long term durability. I imagine they would scratch and get dinged rather quickly, making them more difficult to place.

Aluminum screws are not new, Lowe sold RATS (Ratcheting Aluminum Tubular Screw), which were nearly twice the diameter of modern steel screws with a unique hanger that ratcheted. The entire screw was aluminum, including the teeth, and they were extremely hard to place.

I am still using Black Diamond screws I purchased 23 years ago. I had the teeth re-machined three years ago to match the deep throated teeth on modern screws and they perform better than ever.

The only advantage I can see to the Petzl aluminum screws would be the weight savings, which on an alpine route might be worth the additional cost and reduced durability.

I have a rack of steel (grivel 360) and aluminum (petzl laser speed light) and like them both.

The petzl are less durable. But for casual climbing they last a long time. Just don't pack them loosely in a pile of biners and ice tools:) They crank easily and have good hangars (not the best out of any screwn, but decent).

I haven't fallen on screws, including the petzls. I don't think the steel vs aluminium material would significantly impact the absorbing strength, unless a screw was only partially driven in and it was clipped on the end on the hangar, instead of tied off (or instead of a shorter screw). That's in part because the ice is doing most of the support in structural integrity when fully driven in and loading the ice directly from the hangar, and the threads keep the screw in a place from coming out so that the ice can give that support.