I too have both the 184/116 and 190/118 Bibby Pros. Just got the longer ones this year and am exploring them. Wonderful, as you said.
I agree with almost everything you wrote about them, including they are in a category of their own as both powder
and crud skis that very few skis match, at least ones I've tried or Blistergear has steered me to. Three or four that do match the Bibby's, in my experience as both crud and powder skis: the 189 K2 Pettitors 120 (just this year discontinued) mounted on Schizos or demos, and
with the right forward mount points; 186 K2 Pinnacle 105 from the past few years (
if edge detuned/modified properly, just at the forward contact point); and both the 184 and 191 V-Werks Katanas. All have their strengths and weaknesses. The 186 Pinnacle 105s, for instance, stay in the car on the deepest, heaviest days. (Not sure this is really necessary, but I've just done it anyway.)
After a bad snowboarder collision a few years back, my knee acts up with the relatively heavy Pettitors, but a younger, sounder guy would love them as I still do. (Shorter versions don't have enough fore-aft stability at speed to qualify here.)
I've alternated the Katanas and Bibbys the past few years on powder days, and both rock as powder/crud stars, about equally. Different, but equal, with modestly different strengths and weaknesses.
But the 184 Katana is definitely the spring big slush/crud winner. For me, it's not close between it and the shorter Bibby. (For me, the longer Katanas gain nothing on the shorter in these conditions, except slight loss of quickness. And I have yet to try the longer Bibbys in spring crud/slush; looking forward to it.
)
This year, in all the record heavier snow we've gotten in the Rockies, I've had to adjust my evaluations, skiing - and mount positions. The 189 Pettitors at times I have set back from a +3 1/4 // +3 3/4 or even +4 range to a +2 1/2 // +3 1/4 range, and these still are the best, for me, of these skis, often (but my knee suffers). And they are awfully fat (like the longer Bibbys). The longer Bibbys and the longer Katanas I've had to adjust mount point back as well, at times, to keep them optimal. Then they've shined. The shorter 184 Katanas, however, have been simply overpowered, for me, on the deepest heavy snow days, unlike what we've had here in past years. But once things have been skied off into chop/crud from pure heavy powder, then the shorter Katanas start to shine too, eventually. Odd development, though, just this year - after four seasons on the shorter Katanas with no limits found before.
Oddly also, the shorter Bibbys maybe haven't needed to be moved back in heavy snow, for me, as perhaps they are meant to be both playful and chargers, at least for a lighter guy like me. They just become more playful and less chargy in heavy deep I've tried them in (with modified expectations on my part, at times; but not at other times!). But still, depending on the heavy snow, big dump day, this year I've had to juggle things with most of these skis.