I too am having some "problems" with the USA Lead as well as. The USA IIC++ is sounding a bit odd to me as well. I used the USA JP IIC+ Red for comparison as it sounded most like I remember when it was added.
Here's a recording and the preset used. For the recording, the Looper was used to record a simple line then the amp channels were cycled through.
Each amp was run through the same cab, Factory 2 #866 (YA Recto), and each channel was Reset to default (Block>Reset Channel). The only adjustment was in the Level to attempt to match volumes between the amps.
First amp, Channel C, is the Herbie Ch3 - Similar to what I expected of the USA Lead, similar gain structure to clips on Youtube of the USA Lead model.
Second amp, Channel D, is the USA Lead - No real drive to speak of.
Third amp, Channel A, is the USA IIC++ - A bit more drive but not as remembered or expected.
Fourth amp, Channel B, is the USA JP IIC+ Red - Sounds similar to what I remember when it was first added.
EDIT: Guitar used is an Ibanez RGDIR6M with Bare Knuckle Black Dogs