I own the Janome 7700 and free motion quilt with the following settings:
- Push the D1 button to close the needle plate - This ensures the needle more accurately feeds inside the machine.
- DON'T lower your feed dogs! - I've found the machine has some tension issues with the feed dogs down. It works just fine with them up though, so don't bother dropping them for free motion quilting.
- Set your stitch length to 0 - This will mean the feed dogs will still move up and down, but they will not feed your quilt forward.
- Set tension on Auto and match your thread - use the exact same thread color, type, brand, etc in the top as in the bobbin.
I've never used blue bobbin or a different case. Personally I think that's kind of gimmicky and ridiculous to have to buy a new case just for free motion quilting. If it works for regular sewing and piecing, it should work for free motion quilting too.
I do use my machine in an Arrow Gidget 2 table and it not only fits perfectly, but I was able to use the extension table the machine came with as my insert.
I've compared this with the Janome table and they are made out of exactly the same materials, but the Arrow table is actually sturdier and can fit any machine.
And the price difference really is nice - Gidget 2 tables cost $169.99 - much cheaper!