I've been using what I believe to be the same hard drive in question for awhile, and while it is a little bit of a pain every now and then, it's not too big a downfall.
Only issues I've had are when trying to have my CFG forwarder channel boot to CFG on my hard drive, it takes a few tries some times, like if I take too long picking the channel the drive spins down or something and the forwarder gives up looking for the drive and instead reboots to the system menu to give me another try. But it eventually loads, and after that I simply pick the game I want to play and have no further problems when in game. The only other thing was that WiiMC didn't always want to pick up the drive, but like 80 percent of the time it usually would, and when it didn't would only require either I unplug and plug the drive back in or maybe just restart WiiMC.
Hope this helps, any other questions?
Edit: Oh, and I believe a easy solution to the CFG forwarder problem would be to put the USB loader files onto my SD card itself instead of trying to boot off the hard drive, because it seems once in CFG, it will have no problem powering the drive and finding it to select. I've just been too lazy to move the files over, and I kinda wanted to not have to have all the image covers taking up space on my SD card.