[Steeeeeve]

Are the HD58X really that much of a better deal than the HD6XX, which are also in stock from Massdrop for $200?

 

[chimney189]

Are the HD58X really that much of a better deal than the HD6XX, which are also in stock from Massdrop for $200?

No. They are two completely different sound signatures.
I prefer the 6XX more. The 58X is too bright for my tastes.

 

[kukkurovaca]

Are the HD58X really that much of a better deal than the HD6XX, which are also in stock from Massdrop for $200?

The HD58X is much easier to drive, which is probably one reason why it was suggested in this case. (OP doesn't have/want an amp, right? They're listening from their laptop, I think.)