Interesting to see such a polarised response. I love my amplug. I use a set of Sennhiser 202 headphones with it, and with my P bass '(79, with 9 month old flats) it sounds thick and fat, but I do keep my tone control rolled all the way down, as I generally find it sounds messy with the tone up on a fender, but that's me.
I did try a pandora, and didn't like all the other stuff on it. Just wanted the sound of my bass, with no crap on it, within seconds.
The secret of the amplug is decent headphones, and setting the gain correctly. YMMV.