He asked what the best IOS and cIOS was. I answered the first question.
However I'm wondering, why would it be slow? The only reason I wouldn't use IOS58 for a cIOS is because of compatibility issues.
There is no "best ios". ios are instruction set that games can call upon needed.
The only game that uses ios58 is the mentioned camera game from ubisoft.
Hence the usb 2.0 functions.
And yes you are right, because of issues concerning compatibility for cios ( backup loading etc. )
This ios is used by homebrew to load homebrew apps at 2.0 speed from usb devices THE LEGAL WAY. No cios involved since this official ios was resleased.
Later it became a part of nintendo official 4.3 update ( before it only excited on the gamedisc using this ios ).
This is by no means a "best"ios as this clearly does not make any sense at all.
if I would have to make a pick I've would have said a system menu ios, as for
most users this is mandatory. ( ios 30, 40, 50, 60 ,70, 80...) depending on what version of the sm they are.
The naming of the ios ( numbering) is to keep them structured in a simple way. ( slots )
Theoretically ( & practically ) the code from any slot can be installed in a different slot.
This is the way cioscorp/ darkcorp was setup. Most official ios were replaced with patched ones containing custom ios code. When a game called upon a ios ( slot ) that slot normally is loaded , but now containing a cios, making backuploading possible.
Nowaday usb loader can be directed to use slots, and an installment in a slot not used by nintendo will be sufficient. This way your official sytem files will stay untouched and you are just adding a cios ( or more ) to your existing file structure on wich the wii system relies on.
Normally this would be any slot number above 200. Because of historical reasons, we tend to like ios 249 and 250 as our basic cIOS slots ( Waninkoko slots )
also 222,223,224 are historical Hermes slots ( also a cios dev )
254 is where bootmii ios is installed.
As the years passed this structure was accepted as " norm " for softmods.
Nowadays it possible to install different slots containing cios other than the before mentioned slots. Yet the "Norm" stayed intact .
Some loader allow loading of different slots 247, 248 etc mainly for testing purposes than anything other. What code you have in those slots depends on how you've done your softmod.