How well does the carbon steel hold an edge? I tend to like steels that keep their edge longer than 440c, like 154cm or ATS34 or VG10.
No straight Carbon steel is going to hold an edge longer than 440C. Not a happening thing. Carbides. 440C has them. Carbon steel don't.
But edge geometry rules over alloy choice. GEC has outstanding geometry.
I have not been able to get a hardness measurement of GEC 1095 because GEC anneals the tang of the blade to give it better longevity.
I have compared the edge retention of GEC 1095 to both non-stainless and stainless steels. The comparison involves slicing manila rope. All edge bevels the same. Because it is rope, other differences in blade profile do not affect the comparison.
GEC 1095 had better edge retention than the following:
Carbon V
Schrade 1095
Case CV
GEC 1095 had maybe a tad better edge retention than AUS8 at 59HRC.
It was a definite step below that of Buck 440C at 58HRC.
Mind you this is manila rope slicing and 440C has better abrasion resistance because of the carbide content, so it is going to shine here.
One other caveat. The results above are purely the steel performance. Differences in geometry are negated by the test method.
And GEC blade have outstanding geometry. Real slicers. The edge thickness right above the bevel is ~0.020". I measured both Queen and Camillus stockman blades and they were both ~0.030. This difference can be very significant in cutting things like cardboard.
I think you will be pleasantly surprised by the cutting performance and edge retention of the GEC. Highly recommended.