Two things:

1. Make sure that your number of DLC songs does not exceed 1000 songs with RB3. RB2 can handle more than 1000, but RB3 appears to be built a little differently. Fortunately when you cut out all the songs you don't want, you're left with only the songs you like (mine rests somewhere between 800 and 900 songs).

2. For the first time you launch the game for it to read the DLC, load it from full NAND, not partial NAND. I forget all the technical words and stuff, but the mode where you essentially load up an entirely alternate Wii menu screen, and then load from Uniiloader. After doing this the first time, you'll be able to load from partial NAND from USBLoaderGX for sure (this I find works best for RB3 and DLC, even though I use Wiiflow for just about all other Wii games).

Don't know if this will work for sure or not for you, but it worked for me.

Edit: just realized you may be talking about the vWii and not a standard Wii. I'm not sure if my solution here works or not. While I have a vWii I could test this on, anytime I play RB3 with my friends, we just use my standard Wii.

 

Well, good and bad on my end. I was able to successfully get past that "Loading New Downloaded Content" screen by running the game via Uniiloader on a standard Wii and now that all the DLC content has been loaded, it plays properly on CFG USB Loader on both the standard Wii and the Wii U's Wii Mode (vWii). However, I still have a couple questions about this setup:

1. The "Loading List of Add-on Content" screen that appears prior to the SD card prompt takes forever to load, as does the main menu screen where the "Loading New Download Content" progress bar used to appear. By forever, I mean it takes about 4-5 minutes to load a few hundred songs of DLC content on each and every startup. Is this normal? More importantly, is there any way to speed this up?

A bit OT: Would copying all the content to a 16GB SDHC card improve things speed-wise?

2. Now anytime I decide to remove/reinstall songs on RB3, I'll have to keep a standard Wii around to do it (loading the DLC content to the emuNAND via Uniiloader) before I can use it on the vWii (even though it supposedly supports full emuNAND). That's an extra step I'd like to remove from the process, if possible. Is there any way to get RB3 DLC to load properly via emuNAND using just a vWii setup?

I'd appreciate anyone's answers/opinions on these questions. Thanks!

 

Without emuNAND, load times are fantastic, but then there's no DLC to load...

So for kicks I decided to test the load times on a standard Wii using emuNANDto see if I was exaggerating. Turns out I wasn't. It took 2:24 to load the SD card portion and 2:26 to load the main menu portion, for 4 min., 50 sec. total load time with ~550 DLC songs already installed (no loading bar shows on the menu). I've tried the same load on vWii, a couple different USB loaders, and a NAND emulator, all with similar results. And yet there's no delays at all when running Guitar Hero 6 DLC from emuNAND. I may just have to invest in a 16-32GB SDHC card and take the couple days to convert from emuNAND .APP files to SD .BIN files to improve my load times.

I do find it odd that nobody using emuNAND is really complaining that much about load times (especially of 5 minutes), so perhaps I'm just not as patient as others, or maybe I've done something wrong? It'd be great to have this up and running from emuNAND without such a long wait.

 

That's a bummer, but good to know, so thanks! Unfortunately, my wife and I tried to play RB3 and GH6 tonight on the Wii U (via partial emuNAND) and watched it freeze up after playing just a song or two on both titles. EmuNAND would be great for us, as it'd allow us to switch between using the vWii and standard Wii in different rooms while maintaining our songs and progress, but I haven't had much success using it so far.

I'm going to try out an AC-powered external HDD in place of the USB-powered HDD and see if load speeds/freezing improves, maybe give USB Loader GX a shot as well, but I really wouldn't be surprised if it's just the vWii having issues. I've considered switching to a DLC SD card setup, but it'd mean sacrificing some of my content due to disk space as well as the convenience of emuNAND that I already mentioned.

Is anyone using a partial emuNAND setup successfully (for RB3/GH DLC) on a vWii? I'd be interested in hearing about your setup.

Update #1: I noticed no difference when using AC-powered vs. USB-powered external HDDs, nor was there improved compatibility with other USB loaders. I also discovered that NAND emulation on a standard Wii really hates it if you try to use a vWii-based emuNAND -- shocker. FWIW, loading speeds dramatically improved when running full NAND emulation vs. partial (took less than half the previous time) and did help prevent some crashes. Unfortunately, both GH6 & RB3 still crashed quite frequently on the Wii U system (using Party Shuffle mode, browsing song titles, managing DLC, after finishing songs, etc.).

Update #2: Although it won't be as convenient, I've decided that vWii doesn't play nicely with emuNAND, so I've purchased an SDHC card and will just run the game from the vWii's real NAND to (hopefully) prevent crashes when playing. However, I'd still be interested to hear from anyone who did get an emuNAND setup working succcessfully for RB3/GH DLC on their vWii.