We have some measurements here of the FR20, which shares the same polar response as the FR30 (as it has the same midrange and tweeter configuration).
If you know how to read a polar map, you can see that the directivity is very wide (about 150 degrees) quite constant from 500 Hz to 10 kHz (with a narrowing above that due to the tweeter beaming above 10 kHz.
Excellent!
I surely do not know how to read the polar map, but I can frame it and hang it on the wall next to my FR-30. I like the artistry of it. 
To simplify the graph wide polar dispersion means that the speakers will sound very good way off axis especially if the vertical dispersion is also wide.
As Chris said the tweeters will eventually beam which means just that. They will become a beam of sound (like a flashlight) at a certain high frequency and lose the off axis sound but I dont hear much above 13k anyway so it wouldn’t be a problem for me. 
Wide horizontal dispersion also means that they will sound good when parallel to each other and won’t need much if any toe in unless they are really far apart. That gives the famous wide sound stage and a bigger sweet spot.
The drawback is they will also reflect off more surfaces due to the wide dispersion. Whether that is a problem for your particular situation depends on the room itself.
My T+A’s had very narrow vertical and horizontal dispersion by design so were not very room dependent. They were magic when sitting in the sweet spot.
With that said as soon as you moved out of the chair most of the magic disappeared and they did not sound good at all in the next room FWIW.
Short answer = wide dispersion is a good thing.
It took me a while to realize this, but the FR30 that popped up on TMR did not take long to disappear from TMR.