Sturdy and well built but not perfect (for me) - Tyrant CNC Lightweight Pro Grip

If you want a light weight grip that isn't polymer, this is a decent option. It's a quality piece that is sturdy and quite light. However, I do have some issues with its design.

I really do wish it had a beaver tail to keep your grip centered a little lower. With my grip up towards the receiver I end up with a lot of unused real estate on the lower half of the grip. My three fingers fit in above the last finger groove making the last inch of the grip useless. I wish they would have simply done away with the finger grooves and removed the last half inch or so of grip. It'd be simpler, more comfortable, and save a little weight.

The large center empty space in the sides could use some filling in. The last digit of my pinky slips right into that negative space with the joint right on the edge which is not comfortable.

If you have thicker or bigger hands or commonly shoot with gloves you may not experience these issues.