LaBella Jamersons were the first set of flats I ever bought, after using rounds for almost 2 decades exclusively. I always wanted a P-Bass set up Jamerson style. I bought the strings out of sentiment for my favorite bassist when they first came out on the market and bought the P-Bass later
Anyway, these strings are of great build quality and sound like you'd expect them to, especially with the foam bridge mute. As mentioned above, these strings are heavy and stiff as they get, and will probably require a truss rod adjustment because of that.
As for pros, the Jamerson set delivers what it promises, and a lot of Motown/Jamerson lines seem to "flow" on a P set up with them. They play in tune all over the neck and of of very high quality.
The cons are the expense and the fact that they are physically demanding to play.
