Best x-carve size for aluminum

I’m planning to get an x-carve primarily for cutting aluminum. I’m seeing people are successfully cutting it with the 1000mm but does buying the smaller version actually help with the stiffness cutting metal right out of the box?

The 750 seems like the right size for my intended projects but if the 500 is that much better for successfully cutting aluminum, maybe I should sacrifice cutting area?

That said, if my primary intent is aluminum, should I be looking at another machine altogether?

Yes you’re right. 500X500 is stiffer then bigger ones. If you never need bigger pieces to work on.
We do have many guys working with Aluminum on 1000X1000 with no issues. Al that matters how to assemble your equipment and this forum have tons of ideas.
Besides, if you buy X-Carve now, new ones comes with single rail X Axis which is twice as stiffer than old ones I have.

Our First robotics club cuts mostly AL 6061 and 7075 up to 1/2". Yes, you can cut AL with an x-carve. We used a 500mm X-carve to cut most of our plates for the 2016 season. However, it is not the idea solution. A larger stiffer old Gerber dimension 200 router was donated to us and what a difference. I would not recommend an X-carve for light production of AL. Several other Robot teams have recently purchased Routers like these
X8 series - OMIO CNC Router -omiocnc.com
For real production, you’ll need to spend even more.