Who said anything about lesser production??? Fuck me, the production on Nightside Eclipse is PEEEERRRRFEEEECCCT. I wouldn't change it in the slightest. I love how the vocals sound like they're coming from beyond, or how the keys only accentuate the desolation of it all.
It just transports you into glacier country. Shit, just go read the review. One of the few albums I would seriously give a 10/10. It is a monument in metal.
Don't get me wrong. I like Anthems. But it is black metal by the fucking book. You just cannot deny that - it is well scripted and well coordinated. Some people will call this better songwriting, and in most cases, I would agree.
But Nightside Eclipse is dangerous. You don't know where it's going to take you. It throws you into pitch blackness, and envelopes you in ice. It is impromptu to the utmost degree. It stands against everything that Anthems ended up becoming - a nice studio record with lots of takes, tweaking of knobs, experimenting with mics, adjusting amps....everything to get it sounding 'just right'.
Nightside, on the other hand, is a blitzkrieg. Raw, grim, blood, fire, and motherfucking death.
Case closed.