The JP is a phenomenal amp in its own right, and is far more useful in a band setting. The tone is there in the knobs, the feel is just not quite as organic however it does have the C+ grease which even the MkIIIs don't. A guy could be 100% happy with this amp if he didn't also have an original C+ to compare it to, or if his band was gigging.
Here it is compared to a "normal" amp.
...And here's a comparo I did years ago when I had one of the first JP.