I recently moved to Vancouver and have been skiing Whistler a lot. My current set up is old - 2008 Mantra for soft snow and 2007 Tigershark for hard snow. What I found is that Mantra, at least that model year, is not the best ski for me and the conditions. Whistler powder is heavier, and gets compacted into semi-soft bumps. Not pillowy-nice ones but the ones that are not seer ice but still throw you around at higher speeds. Anyway, I'm sure most know what coastal snow is.
My problem with Mantras is that they float only when I go very fast, but in the skied out wet powder, going very fast is a bit too dangerous, and going slower it's too easy to sink tips, and hard to pull them back up because heavy snow pulls them to the bottom. It's all fixable by changing technique, but it's such a hard work. Also, when skies get bounced around they tire my knees quite a bit because they are heavy and fighting their momentum is also a lot of work.
So I'm looking for a ski that's just as or even more capable, but has better float and is less of a pain/workout to operate in heavier/wetter deep powder and soft bumps.
I'm hearing new Mantra may be that kind, but some friends recommended Prior Husume. I also find new Volkl Katana or V-werks interesting (no brand preference, just looked at what they have now).
I'm a very athletic but not very technical skier, 5'9", 150lbs, high intermediate to advanced - can ski anything confidently, at least in-bounds, but sometimes it does not look perfectly graceful :-).