channels works (they launch), but online doesn't work fine with WiiWare games.
there are two EmuNAND mode :
cIOS : the cIOS is loaded from RealNAND, and the loader launched from RealNAND asks it to redirect all NAND access. It's a "shared" (mixed/not really emulated) mode, as it still run from RealNAND, the Wii can still access NAND and the cIOS redirect some files to SD or USB.
neek : The console boot in a full Emulated environement. There's no cIOS, only official IOS working as if it was a real Wii. The RealNAND is never accessed.
neek mode has better compatibility (as it use real IOS, not patched one), and the nand redirection is not done by the IOS. the IOS doesn't know it's not running on a real Wii.
Wiiflow has both cIOS and neek mode, with 100% compatibility.
USBLoaderGX has only the cIOS mode (90% compatibility, no online with WiiWare).
You can also boot in "neek" mode without a loader. you use Sneek or Uneek or Neek2o, and you will be in emulated System menu where you can access all menus/settings/launch games like if you where on a real Wii.