Which kind of corner bracket is better for 2020 aluminum extrusion?

Which kind of corner bracket is better for 2020 aluminum extrusion? 17x20 piece or 20x28 piece?

A wider grip should technically be more rigid but other factors still apply. Also will the build allow larger brackets without moving to much about to accommodate the size?

Do you really think it matters which?! I’d use (in fact, I did!) the cheapest ones… Not so much forces to really matter the size.

I’d go with the smaller ones (left)

Check if the small one allows you to use socket-head cap screws or if you have to use button head screws. Being forced to use a specific screw type is a pain.

Bigger will be more rigid.

I am with @Ryan_Carlyle ​, go with the bigger ones. More contact area means more strength.

There’s trade offs. The wider stance gives better rigidity, but larger footprint, so you won’t be able to fit things next to it. The extra rigidity is probably unneeded in a 3d printer of this size, but till clearance is definitely better on the larger ones