Modchips still being in their infancy are limited to what they can offer most important feature of any chip is
1) It is Stealth capable, so you can still go online and the wii wont detec the chip
2) Is upgradeable, so with futur update you can flash it VIA dvd or other methods....
3) Can be installed on most/if not all versions of the Wii espeacially the new released version D2B
so far Wiikey is the best, made from the team Xeno, for those who are familiar, are the dudes who released numerous chips across all consoles.
so they are an experienced bunch imo
anyway features for the wiikey are:
Direct boot of wii backups
Direct boot of GC backups
Direct boot of homebrew in GC mode
Supports all currently available console/drive versions
Supports D2B chipsets
Sophisticated (true) update mechanism via DVD (future proof, expect cool features to come)
Direct boot of different NTSC region Wii games/backups on US and JAP consoles
Partial support for NTSC region Wii games/backups on PAL consoles
Boots different region GC games/backups (partially without swapping)
Supports multi-disc games for BOTH Wii and Gamecube
Supports DVD-R / true DVD+R and +RW support (no bitsetting required!)
Improved readsettings for recordable media
Built-in audio fix
Supports fullsize 4GB discs for gamecube homebrew
Stealth mode