you have the choice.
either you use this channel, it's a WiiU homebrew channel which is a vWii booter with sysmenu TitleID patched to boot another channel instead.
so it's : WiiU channel vWii booter -> vWii mode (native) -> vWii UNEO forwarder -> loader's Boot.dol on SD.
Advantage is you are on vWii mode, and has access to cIOS. You can use USB port and devices. You can play Wii games and emuNAND (which require cIOS and USB!) and neek
You don't need to inject all your Wii games one by one and install them on WiiU HDD.
disadvantage is you have to softmod vWii, and you need the forwarder channel installed on vWii NAND too. you don't have WiiU Gamepad support.
OR
you use an injected WiiVC channel with either the loader or the forwarder. (I recommend the forwarder, to prevent having to re-generate a WUP installable channel on each new loader release)
so it's : WiiU VCWii channel injected with forwarder dol -> vWii mode (restricted) -> forwarder dol -> loader's Boot.dol on SD.
Advantage is you boot the loader directly without going into a real vWii mode, and therefore you don't need a hacked/softmod vWii mode. You can use the wiiU gamepad.
If you want Wii games, you need to inject and install them to WiiU sysmenu, I guess having icons on sysmenu is part of "advantage" ?
You can use only one HDD (the WiiU HDD), as you don't need a vWii dedicated FAT32 HDD.
disadvantage is you are in a restricted vWii mode, with NO cIOS, no USB ! you can only use this to launch NAND channels or Gamecube ISO on SD card.
USB, emuNAND and Wii games are not available or playable.
You have to inject all the Wii games and install them to WiiU HDD one by one if you don't want to use native vWii mode at all.
Personally, I prefer native vWii mode.
HDD in FAT32, games are easy to add/move/delete/manage. I don't need to inject or install games to WiiU memory.
I can use features like cheats or patches (wiimmfi, etc.), different settings per games, etc.
I like the "return to loader" feature when exiting a game, instead of return to WiiU sysmenu where you have to relaunch vWii mode and the loader again!
And I don't find launching vWii that annoying, I just press B at console's boot and there I am !
If I'm already in WiiU Mode, I also don't find the channel forwarder necessary, that's really for lazy people who don't want to just launch HBC or forwarder manually once in vWii. that's just one additional click, that's all.
I guess people just love to "see" game's icons on their WiiU menu. I prefer usability over look. each his own