I must say, it works pretty well. I'm getting a bit of lag from it (which I never got in Max's GUI) but on the other hand, this GUI doesn't open up DOS Prompt for each function.
This may be the wrong place to say, but I encountered a strange problem when it came to formatting the USB Drive I've got. I tried creating a 100GB partition, but when it formatted, it only made 32 blocks to work with. Naturally, that's not quite 100GB. Bouncing around formats and I eventually got it all working by formatting to NTFS (the entire 500GB) then formatting to WBFS. After that, everything works great.
EDIT: Well it seems that using NTFS for the 100GB partition works when formatting to WBFS, so I'll use that now. Afterwards I'll put the remaining 400GB back to FAT32. I just wish it didn't take so long to copy 10 games onto it (although I've got many more I want to put on it if it works).
Trying out SSBB (DVD9) atm, but it seems to work. Next I'll try out a few problem games like SSX. I'll also reformat it again to see if I can figure out a way to get a small partition to work (as 500GB is more than I'll ever need). Once I'm done with that battery of tests, I'll try the renaming tests (since most games work). Other than that, I don't know what's left.