JS,
The low-mow bluegrasses have the same issues as bentgrass: they are just as susceptable to dollar spot fungus; they are even more prone to thatch development, hence they require an aeration program of maintenance equal to that of bentgrass. Also they require the same amount of mowing as bentgrass.
On some soils or environments the low mow bluegrasses might get by with a tad less water than bentgrass but they would nonetheless require the same coverage of sprinklers, which is generally the biggest cost associated with irrigation.
And for all of that bentgrass is still a much much better playing surface.
Now if you want to roll the expectations way back to basics, the best bluegrass that I have ever worked with for fast and firm is Merion bluegrass. I've seen unwatered Merion bluegrass fairways turn to straw in plus 100
degree droughts, and after the first rain it came right back, green as can be. But you had to mow it at an inch, and by today's standards that just don't cut it.