The V2 910 is probably the slowest wheel around,

That's kind of what worries me about moving away from a V2 roller ski. I'm not at all in phenomenal shape, but have decent technique, and even with the 910 wheels I find myself kick double-poling or double-poling more than I'd like and overall don't feel like I'm getting much of a workout (I.e., roller-skiing feels more like biking on flats in terms of aerobic training, than it feels like true snow skiing.)

On the other hand, I'm not surprised when you say the Marwe's have a better ride. I'm picking up hints here and there that making a composite ski shaft isn't so straightforward and that Jenex may still be on the early part of the learning curve. Others like Swenor and Ski-Go have been at it longer and may offer a more mature product as a result...