John,
I am not saying that they are bad, but they are very limited and rather difficult to set up for each job.
Everything has to work from one handle, so as you can imagine, for rolling it is turn thru 360 degrees, whereas for shear and bend, it is only a partial movement. Each part cannot be disconnected, so as you are rolling, the guillotine and bender are working at the same time.
You can get small rolls and benders seperately, but I don't think that small bench shears are generally available. None of the facilities on the 3 in 1 are as good or as controllable as you would get from 3 individual small machines.
John