I'll argue that Comet was a good design, but with too many unknowns being solved at once - while we had limited experience with pressurization the comet took more cycles, and had a much higher service ceiling.

I dont think the Comet was a materially worse design than the Avro C102 (both aircraft are similar) and the C102 may very well have had other unknown issues only to be found if it went into series production.