I don't want to sound like a broken record, but when you claim to have warped spacebars, can we at least verify that it has an impact first?
I had warped 9009 spacebars if you placed on a flat surface, but there is no interference or issue when you actually used them. Also, once put on a board, you could not see any visual issues.
I presume people actually use spacebars rather than just put them on display cases to show off how flat they are.
I suppose it may vary from person to person. Some people in this thread appear to have less warping than I do, while others seem to have more. So I can only speak for my own stuff below:
Here is GMK Classic Retro (non-warped spacebar). For reference, the bottom of the spacebar is fairly in-line with the surrounding case.
When swapping in the GMK Cafe gold spacebar, even if you press down pretty hard across the entire surface, it's never quite level. Especially after some short-term usage you can start to see it ride up a bit.
During one test when I was hitting it repeatedly, it became partially dislodged on the other side:
I tried using it normally for maybe a couple of hours, and honestly, for the most part it's fine. That said, I occasionally get strange-feeling presses when the bar shifts a little, and I have to press the whole thing down again. The most obvious thing though is the front aesthetic - that becomes uneven very quickly, though some may not care about that as much. It's sort of hard for me to ignore (personally) so I'm going to try to flatten them out. Not a huge deal -- but I do hope it's an issue GMK can fix in future sets.