This brings up a gorilla in the closet: Do larger skiers necessarily need to be on beefier skis? Or conversely, can lighter skiers find happiness on seriously stiff skis? Obviously the gloss is no. But I can think of some interesting counterexamples, such as our own Dawgcatching, who weighs in at 160 or so, considers himself a power skier, and seems to prefer fairly beefy skis such as Kastles, Blizzards, and Stocklis. For that matter, plenty of lighter WC racers. Conversely, SJ is a bigger guy who considers himself more of a finesse skier and seems particularly to like skis that fall toward the middle, like Nordies, and owned a S7 for two years, no less. Trekchick, cannot speak for whether she's a power or finesse person, has characterized the TST as a easy ski for people who don't like to go fast.
Now for my patented outrageous Fall claim: I think that beefy skis attract at least two populations: Skiers who are pretty good, don't care to constantly adjust their COM to perturbations, and like to go fast (call them # I). And high intermediates to advanced who can't really bend a ski consistently or change their COM quickly enough to adjust, so they ride the radius and let the ski blast through anything that might perturb it (call them # II); if they get back on the tail it's off to the races, but OTOH, it'll also support them for a moment if they can recover. I've seen plenty of intermediates on Mantras, for instance, doing just that, over and over. Notice that I don't mention skier weight, because I think it's mostly irrelevant unless you're above the 90th percentile. Skier height, on the other hand, will be relevant insofar as a stiffer ski will demand some tip pressure if you want to make it do anything outside its innate radius, so stiffer skis may reward a better match to height than moderate flex skis.
Conversely, I think light and moderate flex skis (won't call them soft because aren't many floppy noodles still around, and the term soft has a connotation that biases our thinking) also attract two populations: Intermediates to advanced who aren't technically proficient and don't like speed yet (Trekchick's citation, call them # III). And pretty good skiers who don't mind adjusting their COM to the ongoing pertubations, ski a bit less fast than the I's, and ski terrain where bending the ski, or more generally, having a light ski, is useful (call them # IV). Not sure where qcanoe's friend fits, but have a feeling he's a # IV, regardless of his size.
So you can imagine this as a high school graph, with Y= stiffness and X = skier skill set. Put stiffest to the top, and best skiers to the right. The top right and bottom right quadrants, then, are
Now the glitch is that I think power vs finesse is a third axis, usually called Z. So you can have good power or bad power skiers on stiff or moderate skis, and so on. Here's a graph I just ripped off the web, calls its axes "Dimensions" but this should look familiar to anyone who's ever played with Powerpoint or Excel:
The Dimension 3 might correspond to Power to Finesse, Dimension 2 to Expert to Intermediate, and Dimension 1 to Stiff to Moderate Flex. Individual plots of course would be skiers, and obviously the axes still cross at "0," but the background now gives the increments as a visual convention. What's cool, of course, is that if we had real data, we could actually make such a graph, and see if skiers clustered. As many here know, you can do stuff with these clusters to better characterize them. For instance, don't think power and finesse are intrinsic categories as much as strategies, suspect a good enough skier can morph from one to the other depending on terrain. But the bottom line now that I've geeked out is to suggest we might profit by expanding our thinking past "Good skiers Prefer Skis like 2x4's So They Won't Fold, and Bad Skiers Prefer Noodles That Forgive All." It may depend...