What is the Venge frame being replaced with?
I rode an Aethos a few weeks back, I don't own one, so I have exactly one ride that lasted about an hour. I didn't find it particularly different than my SL7, though it "felt" a bit lighter, when maneuvering. My guess is that it was in my head, because the tubes are noticeably smaller than my SL7. It is plenty stiff, and responded well to power input. I do't know about "jump," but it didn't feel flexy at all. In fact, it didn't feel different from my SL7 in any remarkable way.
If they replace the Venge with an SL7 frame (a big upgrade if you can get Spesh to do it)....have you considered getting something a bit different, like a Roubaix? Not sure what the road surfaces are like where you are, but honestly, for me, it would be a perfect second road bike for the rougher roads (cobbles, light gravel, busted pavement)