Not as comfortable as my 3N2's or Mizuno Blast 2's, but since they're turfs they're still more comfortable than cleats. The ball of my right foot starts to hurt after awhile. I'm a lefty so that's my plant and not pivot foot. It is my stride foot when pitching BP, though.
They do not breathe. At all. There's a ton of padding but it blocks what little mesh there is.
Early ones had problems and it seems they have a bad batch every year, but in terms of durability they're near the top, especially the nubs. I would say I would go through the bottoms of four or even five pairs of 3N2 to every one pair of Boombahs. The 3N2's I have to put on at the field, whereas the Boombah I can put on before I leave, walk through a gravel parking lot, take BP, stop at the grocery store on the way home, etc.
If I had to pick I'd go Mizuno every time, but I'd pretty much go everything Mizuno every time. Their stuff is just generally better. And the 3N2's are more comfy. But the Boombah are way more durable.