Okay, by manufacturer (I'll do the major ones):
Smooth, damp, responsive, requires to user to ski the high end models, but they still do most of the work for you. Not a lot of rebound. Decent edgehold, but solid enough for the average recreational skier (ie: racers need not apply). Retail race skis are slow, but the stock skis are extremely fast - especially GS skis.
Similar to Salomon, same characteristics with slightly more rebound to the ski. Like to ski very round smooth arcs. The retail race skis are not as fast as other companies skis, and cannot be pushed really hard.
The freeride skis are very smooth and like to arc. They tend to be very soft and responsive. The race skis and carver skis however are toward the stiffer end of retail model race skis. This makes them ideal for skiing crud and cut up snow. They will require a fairly aggressive pilot due to their stiff flex. The stock models are very soft and very fast, but awful when not in a course or on perfectly groomed snow (ice).
The skis arc very nicely (buttery smooth). The race skis do not like to let go of a turn however. Once they start to carve they will maintain a carve, thus skidding can be difficult. They usually are known for very good edgehold, but often need a strong heavy skier to realize their potential. Recently they have adopted softer flexing skis, but int he past they were known for very stiff race and freeride skis. Good luck getting race stock skis... if you get them... good luck turning them.
Great race line. Very stiff race skis. Retail models like to turn turn and turn. Stock models are very lively and give good feel for the snow you are traveling over. Not as damp as a french ski - or even an atomic for that matter. The freeride line isnt as popular in the US as other more prevelent companies.
I can only comment on nordica race skis. They are built like tanks, weigh about as much, and have the inertia of a tank. The good part is that they move more like a bullet train. They are smooth, and fast. They soften up after you ski them a few times... or you just stop getting beat up by them. They are very damp - even the slalom ski. Although it is damp it will offer great rebound if you give it the input.
Again - only race skis. Very lively. Least damp of any ski i have ever been on. You can feel every aspect of the terrain you are on. They also go like hell. They also have wonderful edgehold. A very strange feeling if you are used to skiing on a ski like Salomon that lets no vibrations to your foot. They are also surprisingly stiff, and really need to be skied hard - no relaxing.
All race stock construction. Great skis. Powerful. No other company can compare tot he performance you can get out of these skis. Expect to pay for what you get though. If you cant get a race stock ski for a main stream company you can always order one from Stockli... since they only build race stock skis.
They are very stiff skis that need to be pushed, not merely relaxed on. They will give back, but you can easily push them beyond their boundaries unless youre riding a stock race ski. Their freeride skis are very good, but again, very stiff. The stiffness i have found is not always practical, especially if youre under 170lbs. They can be skied by lighter individuals, but dont expect to take it easy.
Very smooth, moderately stiff skis. They love to arc, especially the race skis. Very few recreational skiers will ever be able to out ski their recreational race skis. Forget out skiing the stock skis. The slalom skis have great rebound. The GS skis are very smooth and damp. Edgehold is never a problem, but staying focused on the edge can be a problem.
Head skis are VERY damp. They seem to stick to the snow. When i say stick to the snow they feel like they hug the snow terrain. they turn very easily. I only have experience with one race model, so i cant comment on the race skis a lot.
K2 seems to ski like french skis. They don't have amazing rebound, but they will perform at a high level. The race skis are easy, but slow. The company seems to market more toward recreation rather than race. The freeride/park skis are very good as well. Check out posts on here regarding the new powder skis. Usually you can't go wrong with a K2 for recreational skiing, but i fyou have higher end performance in mind, it is not the route to go.
Thats all for now, i know i left out Line, volant, and a few others, but i figure others can add those. I went through each of those very quickly, so i may have mis-spoke or been vague on a few, but they should convey a general idea of each brand. To get the best view of each brand, try them all. See what you like to ski on. My personal preferences are Salomon, Nordica, and Elan.