Rectangular box is here, think I know what's inside it.
I was right, they're speakers.
They're brand new and sound a bit strident but I have heard enough to form an initial impression: while the LRS was a great speaker for the money, the LRS+ is just a great speaker, period.
I put on Apostrophe' and there's yet another track way down in the mix that I'd never heard before. This may be due to near field listening but that came as a surprise.
There was also one guitar solo that just came BLASTING out of the speakers.
Is the upgrade worth it?
If the rest of your gear is good enough, yes.
I hope they do the plus thing to the rest of the line up.
Good job, Magnepan!