I've have spent WAY too much money on Monitors but my older brother is trying to teach me that good can come out of bad, so maybe if I can help you, that will be good
To answer your questions, yes, I have had experience with all three.
By far the Focal Alpha 65's were the best as far as being more 3D, having a tighter, more accurate bass and more detail and accuracy across the entire mix..
When I mixed on them, the translation as far as how a mix sounded on other systems was better than the other two as well.
You're throwing in the LSR305's which is not apples vs apples.
Of course they would be the easiest to carry around, as they weigh hardly anything.
I'll throw this in as well.
If you have a good ear, you can learn how to mix on any monitors, and once you understand them, you will get the desired result.
As far as the Focal's or Yamaha's being too bulky, how big are you
If it were me, I wouldn't want to carry around the Alpha 65's or the HS8's unprotected, which means I'd have to buy some cases for them and then they would REALLY be big and bulky.
I hope this helps, and if you have any more questions, feel free to ask more
Jerry