I'm sure that all of you like I have found that when skiing in the east on many resorts with little to no side country skiing..a carving ski is ideal...no doubt.
I think an important factor that makes a carving ski is it's turn radius. I went from a Fisher 13m tr to a Kastle 16m tr. AND yes when the snow is hard and or perfect...that 13m tr is just definetly easier to spit out rapid fire turns.
Not trying to be overly technical here, but don't forget that many of the modern carving skis, and even some wider ones, have the dual radius sidecut that makes both short and long turns a breeze. Progressors, Spitfires, past Elan Waveflex, AND your beloved MX78, all have this design. Makes the stated turn radius specs kind of meaningless. And makes those skis so very versatile for skiers who like to mix it up and have a single ski that can do any turn shape they desire.
Gary, I would bet some real coin that if you hadn't discovered the MX78, and found that it is a phenomenally versatile ski (short turns, long turns, hard snow, soft snow, ice.....short of knee deep powder, that ski can do it all with aplomb), you would have a ski in the 72 to 74 mm range as your hard snow carver. The fact that the MX78 exists, and is so good, allows you to have a ski in that width and still rip it up on the hard snow and ice here in the east. Let's face it, I can't think of another ski in that size that compares. To get that kind of hard snow and crud performance, you probably have to go narrower (although the new Progressor 1000 at 78mm might answer nicely). Granted, there are some stiff frontside oriented mid-fats out there in the 80 - 88 mm range (Blizzard, etc.) but I know how you like a playful ski, and I can't see those doing it for you.
Looks like you've finally found the ideal 2-ski quiver that works best for you, in the Kastle and DPS. Knowing you, your evolution is never complete, and the quest for another ski will be renewed in time, but perhaps you'll find inner peace with these for a few years

Ahhhh.....finally some P&Q

As for Mike's first post -- Hey, I agree. Seems to me that the punting of ever-wider skis isn't restricted to the forums. It's in all the ski media as well, at least in the American magazines. A 98mm all-mountain ski for an easterner? Seriously? Do all these writers live in Colorado? Have they ever traveled east of the Mississipi? The Canadian and European media are more balanced. Up here, they realize that the greatest number of skiers lives in the east. This means the greatest number of ski buying customers. Most of them only ski at thier local hill, and never venture west, and therefore don't need more than one ski. So the ski media review and report accordingly. Browsing the racks of our local shops, even the big ones with walls full of skis, including race and high performance models, you would be hard pressed to find a single ski wider than 88 mm. No one wants them, so the stores don't stock them. About 60% - 70% of thier general consumer stock (excluding race skis) are in the 70 to 80 mm range, 20% - 30% twin tips up to 85mm, with a smattering of mid-fats up to 88mm.
Regarding all the forum hype about wide skis, I think Dawgcatching from Epic said it best in this opening paragraph of sub-80mm ski reviews:
http://www.epicski.com/t/99620/2011-sub-80mm-skis-from-fischer-dynastar-kastle-blizzard-head-nordica-stockli-elanCouldn't say it any better myself, and totally spot-on.
Cheers, and enjoy all the new snow.....we FINALLY got some on the ground up here, and first day out is happening, like, NOW!