I have an older version of the 178 Mission and have skied on it for 1.5 seasons. I ski about 80 to 90 days per year and the Missions have been skied on at least 30 days. Note that the 2012 has a slightly different construction and is lighter, but other specs are the same. It might be a totally different ski, but my guess is that the 2012 version is probably similar to mine
The Mission has been a really fun ski. The turn radius in 178 is about 14 meters, and this ski can carve small to wider arcs on groomers but is more like an SL ski. I demoed the E88 on a cruddy day and only for a few runs. Based on my little experience is that I believe that the E88 holds better on hard pack/icy conditions and performs a little better at speed than the Mission. You should look at Dawg's review of the E88. (
( http://www.epicski.com/t/108443/88mm-skis-blizzard-bushwacker-magnum-8-7-elan-apex-head-peak-90-kastle-mx88-rossi-exp-88-volkl-kendo ) On hardpack,the Mission has a good ability to vary turn radius, and is stable. It is nimble and is a good ski for someone who likes to turn. It is stable at speed on hardpack, but probably not as stable as the E88.
The 2010 Mission does rather well in bumps, trees and crud. It is forgiving in bumps and the early rise responds well to an aggressive line. It is easy to turn in the trees, and I probably ski tree runs faster on the Missions than my other skis because it is so nimble. The Mission works quite well in bumpy crud without too much deflection and it absorbs the bumps well. It also does surprisingly well in powder. I had some great days last year at Revelstoke when I forgot to take wider skis and was impressed at how well the Mission did in 12 to 20 inches.
I've come to think of the Mission as my "play ski" because it is fun to ski,is nimble and playful, and is a relaxed but able ski that does well in a variety conditions.