- 'wuds are not dumpable' : Crediar released a discu utility which does just that. Dump a wud file (encrypted) with tickets.
- 'scene never released wuds'
you are mixing "dumping" and "extracting".
You can't dump a game disc to WUD format yourself. you need hardware (probably the unreleased wiikeyu?)
you can decrypt and extract a WUD image to files and folders format with Crediar's DiscU. DiscU does not Dump, it extracts.
Scene groups released WUD format, and eventually stopped because users preferred using loadiine format? but they were released.
loadiine format is not a proper dump (they are marked as nuked releases); it's not clean, but an incomplete extracted format from the console, it contains both game+updates files mixed together. It can also be an extraction of a WUD, which this time will be complete, but still nuked as not being a proper clean 1:1 dump image of a game disc.
Like said by gamesquest, the wud is not incorrect, the wud content is good but the extractor (DiscU and VGMtool) did something wrong which made the extracted ticket bad. we didn't "change the disc to eshop", we just fixed the signature which was bad due to incorrect extraction method.
We are not installing eshop type ticket, the installer sees proper disc tickets.
DiscU has been updated to v4.1b to extract the WUD correctly. (it's not "fixing it while extracting", it's actually "extracting it correctly without breaking it anymore")
to your question : Nus or wud? Which is better?
there's no "better" format here. depends what you want.
if you want a full clean image of a disc, you want WUD. you can extract the WUD to a format used by loadiine. or keep it (compress it to wux to store them efficiently) for any future use.
If you want an encrypted file to use with WUP installer, you want NUS version, and a ticket extracted from WUD or a console.
edit:
I just learn that the new DiscU version can also extract a WUD into encrypted files to be used with WUP Installer.
So, you don't need NUS to get your game, you can just extract the WUD and get either loadiine format, or WUP format.