I think the Sluffs do a lot very well...great soft snow ski...
First off, I am around 225-240 lbs...so you see i need a lot of ski when the snow gets deep...
I live in Colorado, so that has some impact also...
I have the same kind of thought process that you have, get me a skinny ski for it has not snowed for a few days...
In my case that would be the Dynastars...
I have the Sluffs in 184cm length, for when we have new snow, even if is just a couple of inches...
They perform the best when its just a couple of inches, up to boot deep...deeper than that and they start to require more work...
They are fairly stiff in the front, there fore don't float the best in the fluffy stuff we get around here...
They carve on the groomed runs, much much better than you would think...
I think they are great crud busters, not as quick turning as your Progressors would be, but that is to be expected...
I have no problem using them all day when the snow is soft, I ski them with my family in all kinds of conditions...
I am looking to buy that last pair for when the snow is more than boot deep, I will keep the Sluffs and just compliment them....
I will most likely end up with a softer pair of the new Resort Rocker skis, Armada JJ, Rossi S7, CRJ...something along those lines...
That will give me the quiver i need for anything I ski on here...and I admit i am an equipment junkie...