When I had my Pandora Plus trial, my experience was worse than without it. I frequently go back and forth from my phone to desktop. Often, I couldn't listen on my account - I would be told that my account was signed in on another location. Which it was... but I wasn't listening there. It should automatically logout the other location so that I can listen where I am. That was enough to make Pandora Plus a complete no-go for me. I'd rather have commercials than deal with that message and having to go through the hassle of logging and out all the time.
(I imagine this has been mentioned by someone else before me. Feel free to merge.)