I feel like most of the complaints are just "new bad, old good", though there is some good criticism here. I'm the kind of person to write custom userstyles to revert style changes on YouTube, because the purpose of those is usually to make the site less usable, for some reason. Nexus redesign is fine. It's got it's strengths, and some parts I liked better before. It's mostly similar to the old style, just a bit cleaner. The margins are fine, most pages are actually spread to the whole screen width on 1080p, and the margins feel smaller than previously on 1440p.
However, there's one particular reason I've returned to the old design after trying out the beta: the time range filter. The old one had a "from - to" setting, which I used to search for mods made after 2020. The reasoning is that I want to filter out a lot of the old, outdated mods, the "1 year" filter is too limited as I want to catch up with the last few years, and the "trending" view is too biased towards the last month or so. So setting it to "from 01-01-2020 to today" was my less-than-ideal, but functional compromise.
This is no longer possible, and setting the "timeRange" GET argument in the URL manually does nothing, as the API seems to only accept the dropdown values. The perfect solution would be two filters - "uploaded", and "last updated", with the current dropdown options, and a custom time range, like the old one.
And please, please, remove translations from "Mods requiring this file" list, they're already under their own header and pollute the list, or give us a "Required mods" filter setting. I'm begging on my knees.
This helps immensely when working with frameworks, body mods, and other stuff that builds off other mods. Just putting the name of a mod in search queries often brings up stuff that mentions "xxx is incompatible", or FAQ entries that go "xxx support? No", which are really good things to include in your mod description, but the exact opposite of what I'm trying to search for. It gets worse with mods using common words or acronyms, and so on.
I usually use "Mods requiring this file" to search for stuff like "PC Head Tracking and Voice Type" voice packs, but it's a pain in the ass and half the entries are translations I have explicitly filtered out in my preferences.